Add dropdown "primary" style with blue instead of white

app/views/spree/admin/adjustments/_new_form.html.haml

@@ -11,7 +11,8 @@
       = select_tag "adjustment[tax_category_id]",
         options_from_collection_for_select(Spree::TaxCategory.all, :id, :name),
         prompt: t(:none),
-        "data-controller": "tom-select"
+        "data-controller": "tom-select",
+        class: "primary"
       = f.error_message_on :tax_category
 
 .row

app/webpacker/css/admin/components/tom_select.scss

@@ -19,6 +19,27 @@
   background-color: $white;
 }
 
+.ts-wrapper.primary.focus .ts-control,
+.ts-wrapper.primary .ts-control {
+  background-color: $spree-blue;
+  border-color: $spree-blue;
+  color: $white;
+
+  &:after {
+    border-color: $white transparent transparent transparent;
+  }
+}
+
+.ts-wrapper.dropdown-active.primary .ts-control {
+  background-color: $spree-green;
+  border-color: $spree-green;
+  color: $white;
+
+  &:after {
+    border-color: transparent transparent $white transparent;
+  }
+}
+
 .dropdown-input-wrap {
   padding: 0.2em;
 

spec/system/admin/adjustments_spec.rb

@@ -38,7 +38,7 @@ describe '
     click_link 'New Adjustment'
     fill_in 'adjustment_amount', with: 110
     fill_in 'adjustment_label', with: 'Late fee'
-    select2_select 'GST', from: 'adjustment_tax_category_id'
+    select 'GST', from: 'adjustment_tax_category_id'
     click_button 'Continue'
 
     # Then I should see the adjustment, with the correct tax