diff --git a/wagtail/admin/static_src/wagtailadmin/scss/_variables.scss b/wagtail/admin/static_src/wagtailadmin/scss/_variables.scss
index 3d936ce17..862dfe52f 100644
--- a/wagtail/admin/static_src/wagtailadmin/scss/_variables.scss
+++ b/wagtail/admin/static_src/wagtailadmin/scss/_variables.scss
@@ -39,8 +39,8 @@ $color-white: #fff;
 $color-black: #000;
 
 // darker to lighter
-$color-grey-1: darken($color-white, 80);
-$color-grey-2: darken($color-white, 60);
+$color-grey-1: darken($color-white, 90);
+$color-grey-2: darken($color-white, 70);
 
 $color-grey-3: darken($color-white, 15);
 $color-grey-4: darken($color-white, 10);