diff --git a/frontend/packages/shared/src/colors.css b/frontend/packages/shared/src/colors.css
index f9fdd650..8d5381e5 100644
--- a/frontend/packages/shared/src/colors.css
+++ b/frontend/packages/shared/src/colors.css
@@ -183,4 +183,8 @@
   --base0D: var(--mocha-base0D);
   --base0E: var(--mocha-base0E);
   --base0F: var(--mocha-base0F);
+  /* A dark pick over a light OS preference: the media query's shares must not
+     carry over, so the dark palette sets its own, the defaults of theme.css. */
+  --muted-share: 55.5%;
+  --subtext0-share: 77.7%;
 }