Merge pull request #24525 from maheshchandra10/fix(23454)-raw-button-contrast-ratio

UI: Fix button contrast-ratio
(cherry picked from commit ac9880f)

Author: cdedreuille

code/lib/theming/src/themes/light.ts

@@ -21,7 +21,7 @@ const theme: ThemeVars = {
   // Text colors
   textColor: color.darkest,
   textInverseColor: color.lightest,
-  textMutedColor: color.mediumdark,
+  textMutedColor: color.dark,
 
   // Toolbar default and active colors
   barTextColor: color.mediumdark,