Enforce checbox default background color

otherwise, in case validation fails on a checkbox, https://github.com/cprodhomme/arctic_admin/blob/76af378f4fda01783a838d9ea157ce82a6bc6b3b/app/assets/stylesheets/arctic_admin/components/_form.scss#L29..L33 overwrites it and checking only works internally but no visual change can be seen

app/assets/stylesheets/arctic_admin/components/_inputs.scss

@@ -62,7 +62,7 @@ input[type="checkbox"] {
 
   &:checked {
     border-color: $primary-color;
-    background-color: $primary-color;
+    background-color: $primary-color !important;
   }
 }