diff --git a/crates/canvas/src/interaction/ink.rs b/crates/canvas/src/interaction/ink.rs
index ec8d621dfbd1fa456892bb6bcbc9365bd50b2499..510e2e2518bf365f43b6e7d6482901bbda2bae6a 100644
--- a/crates/canvas/src/interaction/ink.rs
+++ b/crates/canvas/src/interaction/ink.rs
@@ -20,7 +20,11 @@ use onestore::{
 pub fn pens(section: [f32; 4]) -> [Pen; 15] {
     let [red, green, blue] = draw::srgb_bytes({
         let [saturation, lightness] = draw::LIGHT_ACCENT;
-        draw::hsl(draw::hue(section), saturation, lightness)
+        draw::hsl(
+            draw::hue(section),
+            saturation * draw::vividness(section),
+            lightness,
+        )
     });
     let accent = Pen::new(35.0, Some(u32::from_le_bytes([red, green, blue, 0])));
     std::array::from_fn(|place| place.checked_sub(1).map_or(accent, |at| FAVORITES[at]))
diff --git a/crates/draw/src/render.rs b/crates/draw/src/render.rs
index 2625eec830b1db3f9542c9784f26a8846988aaa6..93b5d79f5093fa48bfb98e5b4eb29f0b282fcb81 100644
--- a/crates/draw/src/render.rs
+++ b/crates/draw/src/render.rs
@@ -1762,6 +1762,15 @@ pub fn hue(color: [f32; 4]) -> f32 {
     to_hsl([color[0], color[1], color[2]].map(crate::encode))[0]
 }
 
+/// How much of a shade's saturation a linear colour's hue takes, from 0 to 1: all of it from
+/// a saturation of `VIVID` up, as OneNote 2010's bright section colours have, less as the
+/// colour greys, so its Silver and mists stay grey rather than turn their faint hue vivid.
+pub fn vividness(color: [f32; 4]) -> f32 {
+    const VIVID: f32 = 0.35;
+    let [_, saturation, _] = to_hsl([color[0], color[1], color[2]].map(crate::encode));
+    (saturation / VIVID).min(1.0)
+}
+
 /// Hue in degrees, saturation and lightness of an encoded sRGB colour.
 fn to_hsl([r, g, b]: [f32; 3]) -> [f32; 3] {
     let [max, min] = [r.max(g).max(b), r.min(g).min(b)];
diff --git a/crates/ui/src/theme.rs b/crates/ui/src/theme.rs
index 52888a58df2b1097d0cc573efe0192b6935d9148..c71d1289916e3a775467f734046df6325ed8a9d1 100644
--- a/crates/ui/src/theme.rs
+++ b/crates/ui/src/theme.rs
@@ -290,10 +290,12 @@ impl Theme {
         }
     }
 
-    /// The colours a section takes from the hue of `color`, linear RGBA.
+    /// The colours a section takes from the hue of `color`, linear RGBA, as grey as it is.
     pub fn section(&self, color: [f32; 4]) -> Section {
-        let hue = hue(color);
-        let shade = |hue: f32, [saturation, lightness]: [f32; 2]| hsl(hue, saturation, lightness);
+        let (hue, vividness) = (hue(color), draw::vividness(color));
+        let shade = |hue: f32, [saturation, lightness]: [f32; 2]| {
+            hsl(hue, saturation * vividness, lightness)
+        };
         let Shades {
             frame,
             tab,
@@ -326,6 +328,32 @@ mod tests {
         assert_eq!(hsl(240.0, 0.0, 1.0), srgb(0xff, 0xff, 0xff));
     }
 
+    /// OneNote 2010's Silver (`corpus/section-color/native/colors.txt`) shades grey, as
+    /// faint in hue as it is, while its Blue takes the theme's full saturation.
+    #[test]
+    fn grey_sections_stay_grey() {
+        // HSL saturation, as sRGB shows it.
+        let saturation = |color: [f32; 4]| {
+            let [r, g, b] = draw::srgb_bytes(color).map(|byte| f32::from(byte) / 255.0);
+            let [max, min] = [r.max(g).max(b), r.min(g).min(b)];
+            (max - min) / (1.0 - (max + min - 1.0).abs())
+        };
+        for theme in [Theme::light(), Theme::dark()] {
+            let silver = theme.section(srgb(0x95, 0x95, 0xaa));
+            let blue = theme.section(srgb(0x8a, 0xa8, 0xe4));
+            for (silver, blue) in [
+                (silver.tab, blue.tab),
+                (silver.accent, blue.accent),
+                (silver.frame[0], blue.frame[0]),
+            ] {
+                assert!(
+                    saturation(silver) < saturation(blue) * 0.4,
+                    "{silver:?} {blue:?}"
+                );
+            }
+        }
+    }
+
     #[test]
     fn icon_badges_stand_clear_of_the_accent() {
         let badge = |accent_hue: f32| {