Update readonly inputs to use gitlab colors

app/assets/stylesheets/framework/buttons.scss

@@ -497,6 +497,10 @@ fieldset[disabled] .btn,
   }
 }
+[readonly] {
+  cursor: default;
+}
+
 .btn-no-padding {
   padding: 0;
 }

app/assets/stylesheets/framework/variables.scss

@@ -173,11 +173,6 @@ $border-gray-normal: darken($gray-normal, $darken-border-factor);
 $border-gray-normal-dashed: darken($gray-normal, $darken-border-dashed-factor);
 $border-gray-dark: darken($white-normal, $darken-border-factor);
-/*
- * Override Bootstrap 4 variables
- */
-$secondary: $gray-light;
-
 /*
  * UI elements
  */
@@ -810,3 +805,12 @@ Prometheus
 $prometheus-table-row-highlight-color: $theme-gray-100;
 $priority-label-empty-state-width: 114px;
+
+/*
+ * Override Bootstrap 4 variables
+ */
+
+$secondary: $gray-light;
+$input-disabled-bg: $gray-light;
+$input-border-color: $theme-gray-200;
+$input-color: $gl-text-color;

app/assets/stylesheets/pages/search.scss

@@ -18,7 +18,8 @@
 .file-finder-input:hover,
 .issuable-search-form:hover,
 .search-text-input:hover,
-.form-control:hover {
+.form-control:hover,
+:not[readonly] {
   border-color: lighten($dropdown-input-focus-border, 20%);
   box-shadow: 0 0 4px lighten($search-input-focus-shadow-color, 20%);
 }