diff --git a/crates/mobile/src/lib.rs b/crates/mobile/src/lib.rs
index 86b011ad6118f64547a62277af5eb9e12f6e3ede..ec4281c7ce8ee3bcbefa75cd49bb17210afea0ef 100644
--- a/crates/mobile/src/lib.rs
+++ b/crates/mobile/src/lib.rs
@@ -156,8 +156,11 @@ impl Canvas {
         page.host_viewport = true;
         let markdown;
         (page.snap_to_grid, page.editor.default_font, markdown) = options().clone();
-        page.editor.markdown =
-            markdown.then(|| notebook::sidecar::themes::built_in().swap_remove(0).sheet());
+        page.editor.markdown = markdown.then(|| {
+            notebook::sidecar::themes::built_in()
+                .swap_remove(0)
+                .sheet(None)
+        });
         Ok(Self {
             page,
             space,
@@ -733,10 +736,7 @@ impl View {
         surface.configure(gpu.renderer.device(), &config);
         let (mut page, read_only) = section.shared.page(space)?;
         // The page wears its theme: style objects it gives otherwise are restyled first.
-        let sheet = section
-            .theme(page.identity)
-            .map(|theme| theme.sheet())
-            .unwrap_or_default();
+        let sheet = section.sheet(page.identity);
         let restyle = onestore::op::restyle(&page, &sheet)?;
         if !read_only && !restyle.is_empty() {
             section.shared.apply(page_edit(space, restyle))?;
@@ -1118,7 +1118,7 @@ pub extern "C" fn sb_view_style(view: &mut View, place: u8) -> bool {
     let editor = &view.canvas.page.editor;
     let style = editor.styles.get(*name).cloned().unwrap_or_else(|| {
         let theme = built_in().swap_remove(0);
-        definition(name, &theme.styles[*name])
+        definition(name, &theme.styles[*name], None)
     });
     let result = view
         .canvas
diff --git a/crates/mobile/src/library.rs b/crates/mobile/src/library.rs
index f8bc42ed49e51bf95232a199f49cfc07a9859f50..993caaf77378bbc7540ffd8499c1eb0202b9fe7d 100644
--- a/crates/mobile/src/library.rs
+++ b/crates/mobile/src/library.rs
@@ -810,13 +810,29 @@ impl Section {
         ])
     }
 
-    /// The theme page `identity` of this section wears, if any scope names one.
-    pub(crate) fn theme(
+    /// The paragraph styles page `identity` of this section wears in its theme, in this
+    /// section's colour; none where no scope names a theme.
+    pub(crate) fn sheet(
         &self,
         identity: Option<[u8; 16]>,
-    ) -> Option<notebook::sidecar::themes::Theme> {
+    ) -> std::collections::BTreeMap<String, onestore::page::Definition> {
         let section = self.shared.section.identity().ok();
-        self.themes().effective(section, identity)
+        let Some(theme) = self.themes().effective(section, identity) else {
+            return Default::default();
+        };
+        let color = section.and_then(|section| {
+            let notebook = self.library.notebook();
+            let listed = notebook
+                .as_ref()?
+                .catalog()
+                .sections()
+                .find(|listed| listed.file_id == section)?;
+            match listed.state {
+                SectionState::Readable { color, .. } => color,
+                _ => None,
+            }
+        });
+        theme.sheet(color)
     }
 
     /// The section at catalog `path` of `library`, its edits naming `author`.
diff --git a/crates/notebook/src/discover.rs b/crates/notebook/src/discover.rs
index 80b65461a241fc42e7cad78b564b7c5a3faffe67..7b194d230e5c223a053fc49c3e07e1a9ee6a929c 100644
--- a/crates/notebook/src/discover.rs
+++ b/crates/notebook/src/discover.rs
@@ -69,7 +69,7 @@ impl Folder {
     }
 
     /// The sections of this folder and every group under it, in catalog order.
-    pub(crate) fn sections(&self) -> impl Iterator<Item = &Section> {
+    pub fn sections(&self) -> impl Iterator<Item = &Section> {
         self.folders().flat_map(|folder| &folder.sections)
     }
 }
diff --git a/crates/notebook/src/sidecar/themes.rs b/crates/notebook/src/sidecar/themes.rs
index 24a55ae49fc673d7b1cefa9bf523893ca4659fe0..610c782049d5cfe59613f0033782733e24a3b564 100644
--- a/crates/notebook/src/sidecar/themes.rs
+++ b/crates/notebook/src/sidecar/themes.rs
@@ -38,8 +38,12 @@ pub struct ThemeStyle {
     pub size: f32,
     pub bold: bool,
     pub italic: bool,
-    /// `#rrggbb`, or none for automatic.
+    /// `#rrggbb`, or none for automatic. Under `accent`, the accent of a section without a
+    /// colour, which versions that don't know `accent` take.
     pub color: Option<String>,
+    /// Takes the page's section's accent (the "Theme" colour) in place of `color`.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub accent: bool,
     /// Space above and below the paragraph, in points.
     pub before: f32,
     pub after: f32,
@@ -224,16 +228,65 @@ fn is_built_in(id: &str) -> bool {
     built_in().iter().any(|theme| theme.id == id)
 }
 
-/// Stored style `name`'s paragraph style as `style` gives it: every character flag set, as
-/// OneNote 2010 writes its own, headings followed by Normal.
-pub fn definition(name: &str, style: &ThemeStyle) -> Definition {
-    let color = style
-        .color
-        .as_deref()
-        .and_then(|hex| u32::from_str_radix(hex.strip_prefix('#')?, 16).ok())
-        .map_or(0xff00_0000, |rgb| {
-            (rgb >> 16) | (rgb & 0xff00) | ((rgb & 0xff) << 16)
-        });
+/// The accent of a section coloured `section` (a COLORREF; none for OneNote's None), as a
+/// COLORREF: its hue at a fixed saturation and lightness, grey staying grey. Pages store it,
+/// so it never changes: versions resolving it apart would restyle each other's pages.
+pub fn accent(section: Option<u32>) -> u32 {
+    // OneNote's blue for a section without a colour, as Snowbound's tabs show one.
+    let [red, green, blue, _] = section.unwrap_or(0x00E4_A88A).to_le_bytes();
+    let [red, green, blue] = [red, green, blue].map(|byte| f32::from(byte) / 255.0);
+    let (max, min) = (red.max(green).max(blue), red.min(green).min(blue));
+    let range = max - min;
+    let sector = if range == 0.0 {
+        0.0
+    } else if max == red {
+        (green - blue) / range
+    } else if max == green {
+        (blue - red) / range + 2.0
+    } else {
+        (red - green) / range + 4.0
+    };
+    let hue = (sector * 60.0).rem_euclid(360.0);
+    let (saturation, lightness) = (if range == 0.0 { 0.0 } else { 0.60 }, 0.45);
+    let chroma = (1.0 - (2.0 * lightness - 1.0f32).abs()) * saturation;
+    let x = chroma * (1.0 - ((hue / 60.0) % 2.0 - 1.0).abs());
+    let [r, g, b] = match hue {
+        h if h < 60.0 => [chroma, x, 0.0],
+        h if h < 120.0 => [x, chroma, 0.0],
+        h if h < 180.0 => [0.0, chroma, x],
+        h if h < 240.0 => [0.0, x, chroma],
+        h if h < 300.0 => [x, 0.0, chroma],
+        _ => [chroma, 0.0, x],
+    };
+    let byte = |value: f32| {
+        ((value + lightness - chroma / 2.0) * 255.0)
+            .round()
+            .clamp(0.0, 255.0) as u32
+    };
+    byte(r) | byte(g) << 8 | byte(b) << 16
+}
+
+/// A COLORREF as `#rrggbb`, as themes keep colours.
+pub fn color_hex(colorref: u32) -> String {
+    let [red, green, blue, _] = colorref.to_le_bytes();
+    format!("#{red:02X}{green:02X}{blue:02X}")
+}
+
+impl ThemeStyle {
+    /// The style's colour as a COLORREF in a section coloured `section`; none for automatic.
+    pub fn colorref(&self, section: Option<u32>) -> Option<u32> {
+        if self.accent {
+            return Some(accent(section));
+        }
+        let rgb = u32::from_str_radix(self.color.as_deref()?.strip_prefix('#')?, 16).ok()?;
+        Some((rgb >> 16) | (rgb & 0xff00) | ((rgb & 0xff) << 16))
+    }
+}
+
+/// Stored style `name`'s paragraph style as `style` gives it in a section coloured `section`:
+/// every character flag set, as OneNote 2010 writes its own, headings followed by Normal.
+pub fn definition(name: &str, style: &ThemeStyle, section: Option<u32>) -> Definition {
+    let color = style.colorref(section).unwrap_or(0xff00_0000);
     // Paragraph spacing is stored in half inches.
     let stored = |points: f32| points / 36.0 * 36.0;
     Definition {
@@ -261,11 +314,12 @@ pub fn definition(name: &str, style: &ThemeStyle) -> Definition {
 }
 
 impl Theme {
-    /// The paragraph style definitions the theme gives, by stored name.
-    pub fn sheet(&self) -> BTreeMap<String, Definition> {
+    /// The paragraph style definitions the theme gives in a section coloured `section`, by
+    /// stored name.
+    pub fn sheet(&self, section: Option<u32>) -> BTreeMap<String, Definition> {
         self.styles
             .iter()
-            .map(|(name, style)| (name.clone(), definition(name, style)))
+            .map(|(name, style)| (name.clone(), definition(name, style, section)))
             .collect()
     }
 }
@@ -284,6 +338,7 @@ fn style(
         bold,
         italic,
         color: color.map(Into::into),
+        accent: false,
         before,
         after,
     }
@@ -398,7 +453,7 @@ mod tests {
         let document = onestore::document::Document::parse(&index).unwrap();
         let (space, _) = document.pages().unwrap()[0];
         let page = onestore::page::Page::from_space(&document, space).unwrap();
-        let sheet = built_in()[0].sheet();
+        let sheet = built_in()[0].sheet(None);
         for (name, definition) in &sheet {
             assert!(
                 page.definitions.values().any(|stored| stored == definition),
@@ -432,7 +487,7 @@ mod tests {
             .into_iter()
             .find(|theme| theme.id == "manuscript")
             .unwrap()
-            .sheet();
+            .sheet(None);
         let calibri: Vec<&str> = page
             .definitions
             .values()
@@ -470,10 +525,29 @@ mod tests {
         assert!(onestore::op::restyle(&healed, &sheet).unwrap().is_empty());
     }
 
+    /// The "Theme" colour is the section's hue at the accent's shade, OneNote's blue for a
+    /// section without a colour, and grey for a grey section.
+    #[test]
+    fn a_theme_coloured_style_takes_its_section_s_accent() {
+        assert_eq!(color_hex(accent(None)), "#2E5CB8");
+        assert_eq!(color_hex(accent(Some(0x0000_00FF))), "#B82E2E");
+        assert_eq!(color_hex(accent(Some(0x0080_8080))), "#737373");
+        let style = ThemeStyle {
+            accent: true,
+            ..style("Arial", 16.0, BOLD, Some("#2E5CB8"), NONE)
+        };
+        let red = definition("h1", &style, Some(0x0000_00FF));
+        assert_eq!(red.format.color, Some(0x002E_2EB8));
+        // Versions that don't know the accent read the colour beside it.
+        let json = serde_json::to_value(&style).unwrap();
+        assert_eq!(json["color"], "#2E5CB8");
+        assert_eq!(json["accent"], true);
+    }
+
     #[test]
     fn every_built_in_theme_names_every_gallery_style() {
         for theme in built_in() {
-            let sheet = theme.sheet();
+            let sheet = theme.sheet(None);
             for (name, _) in STYLES {
                 assert!(sheet.contains_key(name), "{} {name}", theme.id);
             }
diff --git a/crates/snowbound/src/commands.rs b/crates/snowbound/src/commands.rs
index 8a182a62e6bb83c2b6601c0839d7796a9e1a67c8..60c44f588b294105f00333c88ed30b9d200cb028 100644
--- a/crates/snowbound/src/commands.rs
+++ b/crates/snowbound/src/commands.rs
@@ -136,7 +136,11 @@ pub fn offered(id: Id) -> bool {
 
 /// What the editor's Markdown shortcuts take: OneNote 2010's gallery styles when `on`.
 pub fn markdown(on: bool) -> Option<BTreeMap<String, onestore::page::Definition>> {
-    on.then(|| notebook::sidecar::themes::built_in().swap_remove(0).sheet())
+    on.then(|| {
+        notebook::sidecar::themes::built_in()
+            .swap_remove(0)
+            .sheet(None)
+    })
 }
 
 /// What a menu or toolbar offers: a command, or one of a list's entries.
diff --git a/crates/snowbound/src/library.rs b/crates/snowbound/src/library.rs
index 910a8c0b1d6f2534eaf1319b98997d68991d67f6..cbbb25997a97fc1ffd889f9cf4d2aa2bdd1cdf9c 100644
--- a/crates/snowbound/src/library.rs
+++ b/crates/snowbound/src/library.rs
@@ -1026,6 +1026,18 @@ impl Library {
             .map(|section| section.file_id)
     }
 
+    /// The colour of the section at catalog `path`, COLORREF; none for OneNote's None.
+    pub fn section_color(&self, path: &str) -> Option<u32> {
+        let listed = folders(self.catalog()?, |_| true)
+            .into_iter()
+            .flat_map(|folder| &folder.sections)
+            .find(|section| section.path == path)?;
+        match listed.state {
+            SectionState::Readable { color, .. } => color,
+            _ => None,
+        }
+    }
+
     /// The first readable section, searching groups after sections, as OneNote opens a
     /// notebook.
     pub fn first_section(&self) -> Option<String> {
diff --git a/crates/snowbound/src/main.rs b/crates/snowbound/src/main.rs
index d16d195301afe305848e34344875e0aed6c792d7..34ea45cde11a961956ad3bb00ece27b7be883b7e 100644
--- a/crates/snowbound/src/main.rs
+++ b/crates/snowbound/src/main.rs
@@ -2177,6 +2177,7 @@ impl State {
         let session = self.session.as_ref();
         let update = self.updates.status();
         let sheet = self.gallery_sheet();
+        let section = self.section_color();
         let drawing_pens = self.pens();
         let ui = &mut self.ui;
         let text = theme.text;
@@ -2269,7 +2270,9 @@ impl State {
             .find(|(name, _)| state.style.as_deref() == Some(*name))
             .map_or("Styles".to_owned(), |(_, label)| format!("Styles: {label}"));
         ui::popup::tooltip(ui, &shown, "", None);
-        if let Some(id) = themes::gallery(ui, styles, anchor, &sheet, state.style.as_deref()) {
+        if let Some(id) =
+            themes::gallery(ui, styles, anchor, &sheet, section, state.style.as_deref())
+        {
             choice = Some(Choice::Command(id));
         }
         let combo = ui.id("font");
diff --git a/crates/snowbound/src/menus.rs b/crates/snowbound/src/menus.rs
index c3fa6857dd8f84299e7a007a648e702ee0b5b794..5b22e86dc0c59089c137281ee709ba9b3afaa992 100644
--- a/crates/snowbound/src/menus.rs
+++ b/crates/snowbound/src/menus.rs
@@ -709,13 +709,14 @@ impl State {
             (Target::Section { library, path }, Action::Theme) => {
                 if let Some(identity) = library.section_identity(&path) {
                     let scope = notebook::sidecar::themes::Scope::section(identity);
-                    self.show_themes(crate::themes::Scope::Section, library, scope);
+                    let color = library.section_color(&path);
+                    self.show_themes(crate::themes::Scope::Section, library, scope, color);
                 }
                 None
             }
             (Target::Notebook(library), Action::Theme) => {
                 let scope = notebook::sidecar::themes::Scope::Notebook;
-                self.show_themes(crate::themes::Scope::Notebook, library, scope);
+                self.show_themes(crate::themes::Scope::Notebook, library, scope, None);
                 None
             }
             (Target::Section { library, path }, Action::Color(color)) => Some(Command::Structure(
@@ -843,7 +844,8 @@ impl State {
                 let identity = session.section.page(space).ok()?.identity?;
                 let library = Arc::clone(&session.library);
                 let scope = notebook::sidecar::themes::Scope::page(identity);
-                self.show_themes(crate::themes::Scope::Page, library, scope);
+                let color = self.section_color();
+                self.show_themes(crate::themes::Scope::Page, library, scope, color);
                 None
             }
             Action::Versions(show) => Some(Command::History { page: space, show }),
diff --git a/crates/snowbound/src/themes.rs b/crates/snowbound/src/themes.rs
index ace5be3ce0b8e68da5730c8ca194fc4e49750b79..ec6557246b06bd5e5b6202af376ab370570de245 100644
--- a/crates/snowbound/src/themes.rs
+++ b/crates/snowbound/src/themes.rs
@@ -44,6 +44,8 @@ pub struct Dialog {
     selected: usize,
     /// The style the controls edit, by its place in the gallery.
     style: usize,
+    /// The colour of the section the theme is chosen for, which "Theme" colours take.
+    section: Option<u32>,
 }
 
 fn id() -> Id {
@@ -57,29 +59,24 @@ fn popup(name: &str) -> Id {
 /// Spacing the dialog offers above and below a style, in points.
 const SPACING: [f32; 9] = [0.0, 2.0, 3.0, 4.0, 6.0, 8.0, 10.0, 12.0, 18.0];
 
-/// A style's colour as `#rrggbb` from a COLORREF, and back.
-fn hex(colorref: u32) -> String {
-    let [red, green, blue, _] = colorref.to_le_bytes();
-    format!("#{red:02X}{green:02X}{blue:02X}")
-}
-
-fn colorref(hex: &str) -> Option<u32> {
-    let rgb = u32::from_str_radix(hex.strip_prefix('#')?, 16).ok()?;
-    Some((rgb >> 16) | (rgb & 0xff00) | ((rgb & 0xff) << 16))
-}
-
-/// A line of `text` in `style` as a page shows it, scaled down to fit a menu row up to
-/// `largest` pixels, its colour moved onto the popup's paper so it reads in either scheme.
-pub(crate) fn preview(ui: &mut Ui, part: &str, text: &str, style: &ThemeStyle, largest: f32) {
+/// A line of `text` in `style` as a page in a section coloured `section` shows it, scaled
+/// down to fit a menu row up to `largest` pixels, its colour moved onto the popup's paper so
+/// it reads in either scheme.
+pub(crate) fn preview(
+    ui: &mut Ui,
+    part: &str,
+    text: &str,
+    style: &ThemeStyle,
+    section: Option<u32>,
+    largest: f32,
+) {
     let theme = ui.theme.clone();
     let paper = canvas::gpu::Paper {
         color: theme.popup,
         ink: theme.text,
     };
     let color = style
-        .color
-        .as_deref()
-        .and_then(colorref)
+        .colorref(section)
         .map_or(theme.text, |color| paper.tint(canvas::gpu::colorref(color)));
     ui.leaf(
         part,
@@ -113,6 +110,12 @@ impl State {
         Some((Arc::clone(library), target))
     }
 
+    /// The colour of the open section, which "Theme" colours take.
+    pub(crate) fn section_color(&self) -> Option<u32> {
+        let session = self.session.as_ref()?;
+        session.tabs.get(session.tab)?.color
+    }
+
     /// The theme the open page wears, if any scope names one.
     pub(crate) fn page_theme(&self) -> Option<Theme> {
         let session = self.session.as_ref()?;
@@ -134,7 +137,7 @@ impl State {
     /// Stored style `name` as the gallery applies it on the open page.
     pub(crate) fn gallery_style(&self, name: &str) -> Definition {
         let theme = self.gallery_sheet();
-        stored::definition(name, &theme.styles[name])
+        stored::definition(name, &theme.styles[name], self.section_color())
     }
 
     /// Dresses the open page in its theme: new text and Enter take the theme's styles, and
@@ -142,7 +145,9 @@ impl State {
     /// keeps what it holds.
     pub(crate) fn wear_theme(&mut self) -> Result<(), Box<dyn Error>> {
         let theme = self.page_theme();
-        let sheet = theme.as_ref().map(Theme::sheet).unwrap_or_default();
+        let sheet = (theme.as_ref())
+            .map(|theme| theme.sheet(self.section_color()))
+            .unwrap_or_default();
         self.view.editor.styles = sheet.clone();
         let Some(session) = &self.session else {
             return Ok(());
@@ -164,15 +169,18 @@ impl State {
         let Some((library, target)) = self.theme_target(scope) else {
             return;
         };
-        self.show_themes(scope, library, target);
+        let section = self.section_color();
+        self.show_themes(scope, library, target, section);
     }
 
-    /// Opens the Themes dialog choosing a theme for `target`, which `scope` names.
+    /// Opens the Themes dialog choosing a theme for `target`, which `scope` names, in a
+    /// section coloured `section`.
     pub(crate) fn show_themes(
         &mut self,
         scope: Scope,
         library: Arc<Library>,
         target: stored::Scope,
+        section: Option<u32>,
     ) {
         let themes = library.themes();
         let assigned = themes.assigned(&target).map(|theme| theme.id);
@@ -189,6 +197,7 @@ impl State {
             deleted: Vec::new(),
             selected,
             style: 0,
+            section,
         });
         self.ui.open_popup(id());
     }
@@ -274,7 +283,14 @@ impl State {
                     ..Spec::default()
                 },
             );
-            preview(ui, "name", &listed.name, &listed.styles["h2"], 15.0);
+            preview(
+                ui,
+                "name",
+                &listed.name,
+                &listed.styles["h2"],
+                dialog.section,
+                15.0,
+            );
             if let Some(node) = ui.access(item) {
                 node.set_label(listed.name.as_str());
                 node.set_selected(shown);
@@ -449,24 +465,28 @@ impl State {
         });
         field(ui, "Color:", &mut |ui| {
             let button = ui.id("color");
-            let shown = style.color.clone().unwrap_or_else(|| "Automatic".into());
-            ui::shell::combo(ui, "color", "Color", &shown, 120.0, popup("colors"), true);
+            let shown = match (&style.color, style.accent) {
+                (_, true) => "Theme",
+                (Some(color), false) => color,
+                (None, false) => "Automatic",
+            };
+            ui::shell::combo(ui, "color", "Color", shown, 120.0, popup("colors"), true);
             let swatches: Vec<_> = crate::FONT_COLORS
                 .iter()
                 .map(|&(color, name)| (canvas::gpu::colorref(color), name))
                 .collect();
             let anchor = Anchor::Below(ui.rect(button).unwrap_or_default());
-            if let Some(chosen) =
-                ui::popup::colors(ui, popup("colors"), anchor, "Automatic", &swatches, 10)
+            let buttons = ["Automatic", "Theme"];
+            if let Some(picked) =
+                ui::popup::color_grid(ui, popup("colors"), anchor, &buttons, &swatches, 10)
             {
-                let color = chosen.and_then(|chosen| {
-                    crate::FONT_COLORS
-                        .iter()
-                        .zip(&swatches)
-                        .find(|(_, (swatch, _))| *swatch == chosen)
-                        .map(|((color, _), _)| hex(*color))
-                });
-                change = Some(Change::Color(color));
+                change = match picked {
+                    Ok(chosen) => (swatches.iter())
+                        .position(|(swatch, _)| *swatch == chosen)
+                        .map(|at| Change::Color(Some(stored::color_hex(crate::FONT_COLORS[at].0)))),
+                    Err(0) => Some(Change::Color(None)),
+                    Err(_) => Some(Change::Accent),
+                };
             }
         });
         for (part, label, value) in [
@@ -527,7 +547,7 @@ impl State {
                     ..Spec::default()
                 },
             );
-            preview(ui, "text", label, style, 26.0);
+            preview(ui, "text", label, style, dialog.section, 26.0);
             ui.close();
             if ui.signal(line).clicked {
                 dialog.style = at;
@@ -632,6 +652,8 @@ enum Change {
     Bold,
     Italic,
     Color(Option<String>),
+    /// The section's accent, the "Theme" colour.
+    Accent,
     /// Space above (true) or below, in points.
     Spacing(bool, f32),
 }
@@ -643,7 +665,14 @@ impl Change {
             Self::Size(size) => style.size = size,
             Self::Bold => style.bold = !style.bold,
             Self::Italic => style.italic = !style.italic,
-            Self::Color(color) => style.color = color,
+            Self::Color(color) => {
+                style.color = color;
+                style.accent = false;
+            }
+            Self::Accent => {
+                style.color = Some(stored::color_hex(stored::accent(None)));
+                style.accent = true;
+            }
             Self::Spacing(true, points) => style.before = points,
             Self::Spacing(false, points) => style.after = points,
         }
@@ -656,12 +685,13 @@ fn fresh_id(now: u64, count: usize) -> String {
 }
 
 /// The Styles gallery under the toolbar's Styles button: the eleven styles drawn in
-/// `sheet`, the one at the caret outlined, then the theme commands. Returns the command chosen.
+/// `sheet` in a section coloured `section`, the one at the caret outlined, then the theme commands. Returns the command chosen.
 pub(crate) fn gallery(
     ui: &mut Ui,
     menu: Id,
     anchor: Anchor,
     sheet: &Theme,
+    section: Option<u32>,
     current: Option<&str>,
 ) -> Option<crate::commands::Id> {
     use crate::commands::Id as Cmd;
@@ -689,7 +719,7 @@ pub(crate) fn gallery(
         .get(index)
     {
         Some((name, label)) => {
-            preview(ui, "preview", label, &sheet.styles[*name], 24.0);
+            preview(ui, "preview", label, &sheet.styles[*name], section, 24.0);
             if let Some(node) = ui.access(ui.id("preview")) {
                 node.set_label(*label);
             }
@@ -785,7 +815,7 @@ mod tests {
             let source = onestore::create_section(&file, "", "Author").unwrap();
             let (space, before) = page(&source);
             let mut editor = CanvasEditor::from_page(before, &mut engine).unwrap();
-            let sheet = theme.sheet();
+            let sheet = theme.sheet(None);
             editor.styles = sheet.clone();
             let body = editor
                 .outlines()
@@ -864,7 +894,7 @@ mod tests {
             }
             assert!(op::restyle(&stored, &sheet).unwrap().is_empty());
             // Another theme restyles the page whole, keeping the names.
-            let other = built_in().swap_remove(3).sheet();
+            let other = built_in().swap_remove(3).sheet(None);
             let mut copy = onestore::Section::open(&arena, written.clone()).unwrap();
             copy.apply(
                 "Author",
diff --git a/crates/ui/src/popup.rs b/crates/ui/src/popup.rs
index 046474847c736b6e6115a8c5ac0a95e74ddb4ccb..a5c1a8ff27a33701889926bd8738aee0bda7df61 100644
--- a/crates/ui/src/popup.rs
+++ b/crates/ui/src/popup.rs
@@ -752,26 +752,46 @@ pub fn colors(
     swatches: &[([f32; 4], &str)],
     columns: usize,
 ) -> Option<Option<[f32; 4]>> {
+    color_grid(ui, id, anchor, &[none], swatches, columns).map(Result::ok)
+}
+
+/// `colors` under a button for each of `buttons`: returns the swatch chosen, or the place of
+/// the button.
+pub fn color_grid(
+    ui: &mut Ui,
+    id: Id,
+    anchor: Anchor,
+    buttons: &[&str],
+    swatches: &[([f32; 4], &str)],
+    columns: usize,
+) -> Option<Result<[f32; 4], usize>> {
     if !ui.popup_open(id) {
         return None;
     }
-    // The button is cell 0 and the swatches follow it.
+    // The buttons are the first cells and the swatches follow them.
     let cell = |index: usize| id.child(("cell", index));
-    let count = swatches.len() + 1;
+    let first = buttons.len();
+    let count = swatches.len() + first;
     let (highlight, chosen) = pick_cell(ui, id, count, cell, |key, highlight| {
         match (key, highlight) {
             (_, None) => 0,
             (NamedKey::ArrowLeft, Some(at)) => at.saturating_sub(1),
             (NamedKey::ArrowRight, Some(at)) => (at + 1).min(count - 1),
-            (NamedKey::ArrowUp, Some(at)) => at.saturating_sub(columns),
-            (_, Some(0)) => 1,
+            (NamedKey::ArrowUp, Some(at)) if at < first + columns => {
+                at.min(first).saturating_sub(1)
+            }
+            (NamedKey::ArrowUp, Some(at)) => at - columns,
+            (_, Some(at)) if at < first => at + 1,
             (_, Some(at)) if at + columns < count => at + columns,
             (_, Some(at)) => at,
         }
     });
     if let Some(index) = chosen {
         ui.close_popup(id);
-        return Some((index > 0).then(|| swatches[index - 1].0));
+        return Some(match index.checked_sub(first) {
+            Some(swatch) => Ok(swatches[swatch].0),
+            None => Err(index),
+        });
     }
 
     let theme = ui.theme.clone();
@@ -783,20 +803,22 @@ pub fn colors(
         anchor,
         columns as f32 * CELL + 2.0 * ui.theme.menu().pad,
     );
-    ui.open_as(
-        cell(0),
-        Spec {
-            flags: Flags::CLICKABLE,
-            size: [fill(), px(ROW)],
-            text: Some(none),
-            fill: lit(0),
-            radius: 4.0,
-            pad: [8.0, 0.0],
-            role: Some(Role::MenuItem),
-            ..Spec::default()
-        },
-    );
-    ui.close();
+    for (index, button) in buttons.iter().enumerate() {
+        ui.open_as(
+            cell(index),
+            Spec {
+                flags: Flags::CLICKABLE,
+                size: [fill(), px(ROW)],
+                text: Some(button),
+                fill: lit(index),
+                radius: 4.0,
+                pad: [8.0, 0.0],
+                role: Some(Role::MenuItem),
+                ..Spec::default()
+            },
+        );
+        ui.close();
+    }
     for (row, colors) in swatches.chunks(columns).enumerate() {
         ui.open(
             ("row", row),
@@ -806,7 +828,7 @@ pub fn colors(
             },
         );
         for (column, (color, name)) in colors.iter().enumerate() {
-            let index = 1 + row * columns + column;
+            let index = first + row * columns + column;
             ui.open_as(
                 cell(index),
                 Spec {