common/static/common/styles/_extension.sass

@@ -467,3 +467,12 @@
   .ext-review-list-activity
     display: flex
     +padding(0, x)
+
+.rating-form
+  select
+    color: var(--color-warning)
+
+    &:active,
+    &:hover,
+    &:focus
+      color: var(--color-warning)

ratings/templates/ratings/rating_form.html

@@ -4,7 +4,7 @@
 {% block page_title %}Rate {{ extension.name }}{% endblock page_title %}
 
 {% block content %}
-<div class="container">
+<div class="container rating-form">
   <form method="post" enctype="multipart/form-data">
   {% csrf_token %}
   {% with form=form|add_form_classes %}