fix close buttons color for PageAccessoriesModal

src/client/styles/scss/theme/_apply-colors.scss

@@ -345,15 +345,17 @@ ul.pagination {
     }
   }
 
+  .grw-nav-slide-hr {
+    border-color: $color-link;
+  }
+}
+
+.grw-page-accessories-modal {
   .modal-header {
-    button.close {
+    .close {
       color: $secondary;
     }
   }
-
-  .grw-nav-slide-hr {
-    border-color: $color-link;
-  }
 }
 
 /*