diff --git a/core/modules/color/color.module b/core/modules/color/color.module
index ec1134a..549376a 100644
--- a/core/modules/color/color.module
+++ b/core/modules/color/color.module
@@ -53,21 +53,18 @@ function color_form_system_theme_settings_alter(&$form, &$form_state) {
 }
 
 /**
- * Replaces style sheets with color-altered style sheets.
- *
- * A theme that supports the color module should call this function from its
- * THEME_process_html() function, so that the correct style sheets are
- * included when html.tpl.php is rendered.
+ * Implements hook_css_alter().
  *
- * @see theme()
+ * Replaces style sheets with color-altered style sheets.
  */
-function _color_html_alter(&$vars) {
+function color_css_alter(&$css) {
   global $theme_key;
   $themes = list_themes();
 
   // Override stylesheets.
   $color_paths = config('color.' . $theme_key)->get('stylesheets');
-  if (!empty($color_paths)) {
+
+  if (!empty($color_paths) && !empty($themes[$theme_key]->stylesheets['all'])) {
 
     foreach ($themes[$theme_key]->stylesheets['all'] as $base_filename => $old_path) {
       // Loop over the path array with recolored CSS files to find matching
@@ -78,25 +75,19 @@ function _color_html_alter(&$vars) {
         if (drupal_basename($old_path) == drupal_basename($color_path)) {
           // Replace the path to the new css file.
           // This keeps the order of the stylesheets intact.
-          $vars['css'][drupal_basename($old_path)]['data'] = $color_path;
+          $css[drupal_basename($old_path)]['data'] = $color_path;
         }
       }
     }
-
-    $vars['styles'] = drupal_get_css($vars['css']);
   }
 }
 
 /**
- * Replaces the logo with a color-altered logo.
- *
- * A theme that supports the color module should call this function from its
- * THEME_process_page() function, so that the correct logo is included when
- * page.tpl.php is rendered.
+ * Implements hook_preprocess_page().
  *
- * @see theme()
+ * Replace the logo with the colored version if available.
  */
-function _color_page_alter(&$vars) {
+function color_preprocess_page(&$vars) {
   global $theme_key;
 
   // Override logo.
diff --git a/core/themes/bartik/bartik.theme b/core/themes/bartik/bartik.theme
index 0593a3c..e4f03b9 100644
--- a/core/themes/bartik/bartik.theme
+++ b/core/themes/bartik/bartik.theme
@@ -30,16 +30,6 @@ function bartik_preprocess_html(&$variables) {
 }
 
 /**
- * Implements hook_process_HOOK() for html.tpl.php.
- */
-function bartik_process_html(&$variables) {
-  // Hook into color.module.
-  if (module_exists('color')) {
-    _color_html_alter($variables);
-  }
-}
-
-/**
  * Implements hook_preprocess_HOOK() for page.html.twig.
  */
 function bartik_preprocess_page(&$variables) {
@@ -51,17 +41,8 @@ function bartik_preprocess_page(&$variables) {
   if (!empty($variables['secondary_menu'])) {
     $variables['secondary_menu']['#attributes']['id'] = 'secondary-menu-links';
   }
-}
 
-/**
- * Implements hook_process_HOOK() for page.html.twig.
- */
-function bartik_process_page(&$variables) {
   $site_config = config('system.site');
-  // Hook into color.module.
-  if (module_exists('color')) {
-    _color_page_alter($variables);
-  }
   // Always print the site name and slogan, but if they are toggled off, we'll
   // just hide them visually.
   $variables['hide_site_name']   = theme_get_setting('features.name') ? FALSE : TRUE;
@@ -103,12 +84,8 @@ function bartik_preprocess_maintenance_page(&$variables) {
     $variables['site_name'] = '';
   }
   drupal_add_css(drupal_get_path('theme', 'bartik') . '/css/maintenance-page.css');
-}
+  $variables['styles'] = drupal_get_css();
 
-/**
- * Implements hook_process_HOOK() for maintenance-page.html.twig.
- */
-function bartik_process_maintenance_page(&$variables) {
   $site_config = config('system.site');
   // Always print the site name and slogan, but if they are toggled off, we'll
   // just hide them visually.