diff --git a/docs/web-ui/design-guide.md b/docs/web-ui/design-guide.md
index 5593710f..e8610471 100644
--- a/docs/web-ui/design-guide.md
+++ b/docs/web-ui/design-guide.md
@@ -32,9 +32,10 @@ repeated here.
   model selector living in a three-dot overflow menu instead of next to
   the thing that shows the current model.
 - Loosely influenced by Material Design's current (Material You)
-  generation, mainly for shape/elevation ideas — colour theming is
-  governed entirely by the base16/stylix contract below, not Material's
-  dynamic-colour system.
+  generation, mainly for shape/elevation ideas. Colour is dynamic too —
+  auto-derived shades (mixing, lighter/darker) are fair game, same as
+  Material's own approach — but every derived colour still traces back
+  to the base16/stylix contract below, never an independent source.
 
 ## Motion