Bootstrapの色変数における map-mergeの記述を追加。

src/client/styles/scss/_override-bootstrap-variables.scss

@@ -22,7 +22,30 @@ $gray-600: lighten($dark, 10%) !default;
 $gray-700: lighten($dark, 5%) !default;
 $gray-800: $dark !default;
 $gray-900: darken($dark, 5%) !default;
+$grays: () !default;
+$grays: map-merge(
+  (
+    "50": $gray-50,
+    "100": $gray-100,
+    "200": $gray-200,
+    "300": $gray-300,
+    "400": $gray-400,
+    "500": $gray-500,
+    "600": $gray-600,
+    "700": $gray-700,
+    "800": $gray-800,
+    "900": $gray-900
+  ),
+  $grays
+);
+
 $red: #ff0a54 !default;
+$colors: map-merge(
+  $colors,
+  (
+    "red": $red
+  )
+);
 
 //== Typography
 //