Revert "Merge branch...

Revert "Merge branch '249640-ux-debt-from-visually-emphasize-collapsed-mr-diff-files' into 'master'"

This reverts commit aeaad372.

app/assets/javascripts/diffs/components/diff_file.vue

@@ -209,14 +209,15 @@ export default {
           <div v-safe-html="errorMessage" class="nothing-here-block"></div>
         </div>
         <template v-else>
-          <div
-            v-show="isCollapsed"
-            class="gl-p-7 gl-bg-gray-10 gl-text-center collapsed-file-warning"
-          >
+          <div v-show="isCollapsed" class="gl-p-7 gl-text-center collapsed-file-warning">
             <p class="gl-mb-8 gl-mt-5">
               {{ $options.i18n.collapsed }}
             </p>
-            <gl-button class="gl-mb-5" data-testid="expandButton" @click="handleToggle">
+            <gl-button
+              class="gl-alert-action gl-mb-5"
+              data-testid="expandButton"
+              @click="handleToggle"
+            >
               {{ $options.i18n.expand }}
             </gl-button>
           </div>

changelogs/unreleased/maintenance-design-collapsed-files.yml

----
-title: Color/position tweaks for collapsed diff files
-merge_request: 42465
-author:
-type: other