diff --git a/core/includes/common.inc b/core/includes/common.inc
index 52cb151..f05211c 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -2118,7 +2118,7 @@ function drupal_hex_to_rgba($hex, $alpha = FALSE) {
   }
 
   // The input is invalid, if alpha is not allowed but given.
-  if (!$alpha && !empty($rgba['alpha'])) {
+  if (!$alpha && isset($rgba[4])) {
     return FALSE;
   }
 
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 7ab297a..0a47407 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -427,7 +427,6 @@ function system_element_info() {
   );
   $types['color'] = array(
     '#input' => TRUE,
-    '#alpha' => FALSE,
     '#default_value' => '#000000',
     '#process' => array('ajax_process_form'),
     '#element_validate' => array('form_validate_color'),
diff --git a/core/modules/system/tests/common.test b/core/modules/system/tests/common.test
index 626a872..0a12240 100644
--- a/core/modules/system/tests/common.test
+++ b/core/modules/system/tests/common.test
@@ -2108,6 +2108,11 @@ class CommonColorConversionTestCase extends DrupalUnitTestCase {
     $this->assertIdentical(drupal_hex_to_rgba('#a00f', TRUE), FALSE);
     $this->assertIdentical(drupal_hex_to_rgba('#aa00aaf1', TRUE), FALSE);
 
+    // Test alpha values are invalid if they are not allowed.
+    $this->assertIdentical(drupal_hex_to_rgba('#1111'), FALSE);
+    $this->assertIdentical(drupal_hex_to_rgba('#22334455'), FALSE);
+    $this->assertIdentical(drupal_hex_to_rgba('#0000'), FALSE);
+
     // Test bogus input.
     $this->assertIdentical(drupal_hex_to_rgba('#foo'), FALSE);
     $this->assertIdentical(drupal_hex_to_rgba('123456789'), FALSE);
diff --git a/core/themes/bartik/css/style.css b/core/themes/bartik/css/style.css
index 7ab3d4e..3563b44 100644
--- a/core/themes/bartik/css/style.css
+++ b/core/themes/bartik/css/style.css
@@ -1194,6 +1194,7 @@ input.form-email,
 input.form-url,
 input.form-search,
 input.form-number,
+input.form-color,
 textarea.form-textarea,
 select.form-select {
   border: 1px solid #ccc;
diff --git a/core/themes/seven/style.css b/core/themes/seven/style.css
index a3d6773..9e807d5 100644
--- a/core/themes/seven/style.css
+++ b/core/themes/seven/style.css
@@ -612,6 +612,7 @@ div.teaser-checkbox .form-item,
 .form-disabled input.form-url,
 .form-disabled input.form-search,
 .form-disabled input.form-number,
+.form-disabled input.form-color,
 .form-disabled input.form-file,
 .form-disabled textarea.form-textarea,
 .form-disabled select.form-select {
@@ -703,6 +704,7 @@ input.form-email,
 input.form-url,
 input.form-search,
 input.form-number,
+input.form-color,
 input.form-file,
 textarea.form-textarea,
 select.form-select {
@@ -721,6 +723,7 @@ input.form-email:focus,
 input.form-url:focus,
 input.form-search:focus,
 input.form-number:focus,
+input.form-color:focus,
 input.form-file:focus,
 textarea.form-textarea:focus,
 select.form-select:focus {