diff --git a/core/modules/color/color.js b/core/modules/color/color.js
index f9eebf2..59e64cf 100644
--- a/core/modules/color/color.js
+++ b/core/modules/color/color.js
@@ -21,8 +21,8 @@
       var focused = null;
 
       // Add Farbtastic.
-      $('<div id="placeholder"></div>').once('color').prependTo(form);
-      var farb = $.farbtastic('#placeholder');
+      $('<div class="color-placeholder"></div>').once('color').prependTo(form);
+      var farb = $.farbtastic('.color-placeholder');
 
       // Decode reference colors to HSL.
       var reference = settings.color.reference;
@@ -39,8 +39,8 @@
       for (i in settings.gradients) {
         if (settings.gradients.hasOwnProperty(i)) {
           // Add element to display the gradient.
-          $('#preview').once('color').append('<div id="gradient-' + i + '"></div>');
-          var gradient = $('#preview #gradient-' + i);
+          $('.color-preview').once('color').append('<div id="gradient-' + i + '"></div>');
+          var gradient = $('.color-preview #gradient-' + i);
           // Add height of current gradient to the list (divided by 10).
           height.push(parseInt(gradient.css('height'), 10) / 10);
           // Add width of current gradient to the list (divided by 10).
@@ -143,14 +143,14 @@
           if (propagate) {
             i = input.i;
             for (j = i + 1; ; ++j) {
-              if (!locks[j - 1] || $(locks[j - 1]).is('.unlocked')) {
+              if (!locks[j - 1] || $(locks[j - 1]).is('.is-unlocked')) {
                 break;
               }
               matched = shift_color(color, reference[input.key], reference[inputs[j].key]);
               callback(inputs[j], matched, false);
             }
             for (j = i - 1; ; --j) {
-              if (!locks[j] || $(locks[j]).is('.unlocked')) {
+              if (!locks[j] || $(locks[j]).is('.is-unlocked')) {
                 break;
               }
               matched = shift_color(color, reference[input.key], reference[inputs[j].key]);
@@ -198,7 +198,7 @@
       }
 
       // Initialize color fields.
-      form.find('#palette input.form-text')
+      form.find('.js-color-palette input.form-text')
         .each(function () {
           // Extract palette field name
           this.key = this.id.substring(13);
@@ -210,23 +210,23 @@
           i = inputs.length;
           if (inputs.length) {
             var toggleClick = true;
-            var lock = $('<div class="lock"></div>').on('click', function () {
+            var lock = $('<div class="color-palette__lock"></div>').on('click', function () {
               if (toggleClick) {
-                $(this).addClass('unlocked');
+                $(this).addClass('is-unlocked');
                 $(hooks[i - 1]).attr('class',
-                  locks[i - 2] && $(locks[i - 2]).is(':not(.unlocked)') ? 'hook up' : 'hook'
+                  locks[i - 2] && $(locks[i - 2]).is(':not(.is-unlocked)') ? 'color-palette__hook is-up' : 'color-palette__hook'
                 );
                 $(hooks[i]).attr('class',
-                  locks[i] && $(locks[i]).is(':not(.unlocked)') ? 'hook down' : 'hook'
+                  locks[i] && $(locks[i]).is(':not(.is-unlocked)') ? 'color-palette__hook is-down' : 'color-palette__hook'
                 );
               }
               else {
-                $(this).removeClass('unlocked');
+                $(this).removeClass('is-unlocked');
                 $(hooks[i - 1]).attr('class',
-                  locks[i - 2] && $(locks[i - 2]).is(':not(.unlocked)') ? 'hook both' : 'hook down'
+                  locks[i - 2] && $(locks[i - 2]).is(':not(.is-unlocked)') ? 'color-palette__hook is-both' : 'color-palette__hook is-down'
                 );
                 $(hooks[i]).attr('class',
-                  locks[i] && $(locks[i]).is(':not(.unlocked)') ? 'hook both' : 'hook up'
+                  locks[i] && $(locks[i]).is(':not(.is-unlocked)') ? 'color-palette__hook is-both' : 'color-palette__hook is-up'
                 );
               }
               toggleClick = !toggleClick;
@@ -236,17 +236,17 @@
           }
 
           // Add hook.
-          var hook = $('<div class="hook"></div>');
+          var hook = $('<div class="color-palette__hook"></div>');
           $(this).after(hook);
           hooks.push(hook);
 
-          $(this).parent().find('.lock').trigger('click');
+          $(this).parent().find('.color-palette__lock').trigger('click');
           this.i = i;
           inputs.push(this);
         })
         .on('focus', focus);
 
-      form.find('#palette label');
+      form.find('.js-color-palette label');
 
       // Focus first color.
       inputs[0].focus();
diff --git a/core/modules/color/css/color.admin.css b/core/modules/color/css/color.admin.css
index 5da8c35..1d014ce 100644
--- a/core/modules/color/css/color.admin.css
+++ b/core/modules/color/css/color.admin.css
@@ -27,56 +27,56 @@
 [dir="rtl"] .color-form .form-text {
   float: right;
 }
-#palette .hook {
+.color-palette__hook {
   float: left; /* LTR */
   width: 16px;
   height: 16px;
 }
-[dir="rtl"] #palette .hook {
+[dir="rtl"] .color-palette__hook {
   float: right;
 }
-#palette .down,
-#palette .up,
-#palette .both {
+.color-palette__hook.is-down,
+.color-palette__hook.is-up,
+.color-palette__hook.is-both {
   background: url(../images/hook.png) no-repeat 100% 0; /* LTR */
 }
-[dir="rtl"] #palette .down,
-[dir="rtl"] #palette .up,
-[dir="rtl"] #palette .both {
+[dir="rtl"] .color-palette__hook.is-down,
+[dir="rtl"] .color-palette__hook.is-up,
+[dir="rtl"] .color-palette__hook.is-both {
   background: url(../images/hook-rtl.png) no-repeat 0 0;
 }
-#palette .up {
+.color-palette__hook.is-up {
   background-position: 100% -27px; /* LTR */
 }
-[dir="rtl"] #palette .up {
+[dir="rtl"] .color-palette__hook.is-up {
   background-position: 0 -27px;
 }
-#palette .both {
+.color-palette__hook.is-both {
   background-position: 100% -54px; /* LTR */
 }
-[dir="rtl"] #palette .both {
+[dir="rtl"] .color-palette__hook.is-both {
   background-position: 0 -54px;
 }
-#palette .lock {
+.color-palette__lock {
   float: left; /* LTR */
   width: 20px;
   height: 19px;
   background: url(../images/lock.png) no-repeat 50% 0;
   cursor: pointer;
 }
-[dir="rtl"] #palette .lock {
+[dir="rtl"] .color-palette__lock {
   float: right;
 }
-#palette .unlocked {
+.is-unlocked {
   background-position: 50% -22px;
 }
 
 /* wide viewport. */
 @media screen and (min-width: 37.5625em) { /* 601px */
-  #placeholder {
+  .color-placeholder {
     float: right; /* LTR */
   }
-  [dir="rtl"] #placeholder {
+  [dir="rtl"] .color-placeholder {
     float: left;
   }
   .color-form .form-item {
@@ -103,17 +103,17 @@
   [dir="rtl"] .color-form .form-select {
     float: right;
   }
-  #palette .hook {
+  .color-palette__hook {
     float: left; /* LTR */
     margin-top: 3px;
   }
-  [dir="rtl"] #palette .hook {
+  [dir="rtl"] .color-palette__hook {
     float: right;
   }
-  #palette .lock {
+  .color-palette__lock {
     float: left; /* LTR */
   }
-  [dir="rtl"] #palette .lock {
+  [dir="rtl"] .color-palette__lock {
     float: right;
   }
 }
@@ -122,20 +122,20 @@
 }
 
 /* Preview */
-#preview {
+.color-preview {
   display: none;
 }
-.js #preview {
+.js .color-preview {
   display: block;
   position: relative;
   float: left; /* LTR */
 }
-.js[dir="rtl"] #preview {
+.js[dir="rtl"] .color-preview {
   float: right;
 }
 @media screen and (max-width: 30em) { /* 480px */
-  .color-form #preview-sidebar,
-  .color-form #preview-content {
+  .color-form .color-preview-sidebar,
+  .color-form .color-preview-content {
     width: auto;
     margin: 0;
   }
diff --git a/core/modules/color/preview.html b/core/modules/color/preview.html
index e25b7ad..d89edcb 100644
--- a/core/modules/color/preview.html
+++ b/core/modules/color/preview.html
@@ -1,7 +1,7 @@
-<div id="preview">
+<div class="color-preview">
   <div id="text">
     <h2>Lorem ipsum dolor</h2>
     <p>Sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud <a href="#">exercitation ullamco</a> laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
   </div>
   <div id="img"></div>
-</div>
\ No newline at end of file
+</div>
diff --git a/core/modules/color/preview.js b/core/modules/color/preview.js
index 4c99ffa..56bbfe3 100644
--- a/core/modules/color/preview.js
+++ b/core/modules/color/preview.js
@@ -11,11 +11,11 @@
     callback: function (context, settings, form, farb, height, width) {
       var accum, delta;
       // Solid background.
-      form.find('#preview').css('backgroundColor', form.find('#palette input[name="palette[base]"]').val());
+      form.find('.color-preview').css('backgroundColor', form.find('.color-palette input[name="palette[base]"]').val());
 
       // Text preview
-      form.find('#text').css('color', form.find('#palette input[name="palette[text]"]').val());
-      form.find('#text a, #text h2').css('color', form.find('#palette input[name="palette[link]"]').val());
+      form.find('#text').css('color', form.find('.color-palette input[name="palette[text]"]').val());
+      form.find('#text a, #text h2').css('color', form.find('.color-palette input[name="palette[link]"]').val());
 
       function gradientLineColor(i, element) {
         for (var k in accum) {
@@ -30,8 +30,8 @@
       var color_start, color_end;
       for (var i in settings.gradients) {
         if (settings.gradients.hasOwnProperty(i)) {
-          color_start = farb.unpack(form.find('#palette input[name="palette[' + settings.gradients[i].colors[0] + ']"]').val());
-          color_end = farb.unpack(form.find('#palette input[name="palette[' + settings.gradients[i].colors[1] + ']"]').val());
+          color_start = farb.unpack(form.find('.color-palette input[name="palette[' + settings.gradients[i].colors[0] + ']"]').val());
+          color_end = farb.unpack(form.find('.color-palette input[name="palette[' + settings.gradients[i].colors[1] + ']"]').val());
           if (color_start && color_end) {
             delta = [];
             for (var j in color_start) {
diff --git a/core/modules/color/templates/color-scheme-form.html.twig b/core/modules/color/templates/color-scheme-form.html.twig
index 694c6f7..96a4266 100644
--- a/core/modules/color/templates/color-scheme-form.html.twig
+++ b/core/modules/color/templates/color-scheme-form.html.twig
@@ -17,7 +17,7 @@
 #}
 <div class="color-form clearfix">
   {{ form.scheme }}
-  <div id="palette" class="clearfix">
+  <div class="clearfix js-color-palette">
     {{ form.palette }}
   </div>
   {{ form|without('scheme', 'palette') }}
diff --git a/core/themes/bartik/color/preview.css b/core/themes/bartik/color/preview.css
index 294277f..0e64b5f 100644
--- a/core/themes/bartik/color/preview.css
+++ b/core/themes/bartik/color/preview.css
@@ -1,9 +1,9 @@
 /* ---------- Preview Styles ----------- */
-.js #preview {
+.js .color-preview {
   clear: both;
   float: none !important;
 }
-#preview {
+.color-preview {
   background-color: #fff;
   font-family: Georgia, "Times New Roman", Times, serif;
   font-size: 14px;
@@ -12,15 +12,15 @@
   word-wrap: break-word;
   margin-bottom: 10px;
 }
-#preview-header {
+.color-preview-header {
   font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
   position: relative;
 }
-#preview-logo {
+.color-preview-logo {
   float: left;
   padding: 15px;
 }
-#preview-site-name {
+.color-preview-site-name {
   color: #686868;
   font-weight: normal;
   font-size: 1.821em;
@@ -29,24 +29,24 @@
   margin-left: 15px; /* LTR */
   padding-top: 34px;
 }
-[dir="rtl"] #preview-site-name {
+[dir="rtl"] .color-preview-site-name {
   margin-left: 0;
   margin-right: 15px;
 }
-#preview-main-menu {
+.color-preview-main-menu {
   clear: both;
   padding: 0 15px 3px;
 }
-#preview-main-menu-links a {
+.color-preview-main-menu-links a {
   color: #d9d9d9;
   padding: 0.6em 1em 0.4em;
 }
-#preview-main-menu-links {
+.color-preview-main-menu-links {
   font-size: 0.929em;
   margin: 0;
   padding: 0;
 }
-#preview-main-menu-links a {
+.color-preview-main-menu-links a {
   color: #333;
   background: #ccc;
   background: rgba(255, 255, 255, 0.7);
@@ -54,54 +54,54 @@
   border-top-left-radius: 8px;
   border-top-right-radius: 8px;
 }
-#preview-main-menu-links a:hover,
-#preview-main-menu-links a:focus {
+.color-preview-main-menu-links a:hover,
+.color-preview-main-menu-links a:focus {
   background: #eee;
   background: rgba(255, 255, 255, 0.95);
   text-decoration: none;
   cursor: pointer;
 }
-#preview-main-menu-links li a.active {
+.color-preview-main-menu-links li a.active {
   background: #fff;
   border-bottom: none;
 }
-#preview-main-menu-links li {
+.color-preview-main-menu-links li {
   display: inline;
   list-style-type: none;
   padding: 0.6em 0 0.4em;
 }
-#preview-sidebar,
-#preview-content {
+.color-preview-sidebar,
+.color-preview-content {
   display: inline;
   float: left; /* LTR */
   position: relative;
 }
-[dir="rtl"] #preview-sidebar,
-[dir="rtl"] #preview-content {
+[dir="rtl"] .color-preview-sidebar,
+[dir="rtl"] .color-preview-content {
     float: right;
 }
-#preview-sidebar {
+.color-preview-sidebar {
   margin-left: 15px; /* LTR */
   width: 210px;
 }
-[dir="rtl"] #preview-sidebar {
+[dir="rtl"] .color-preview-sidebar {
   margin-left: 0;
   margin-right: 15px;
 }
-#preview-content {
+.color-preview-content {
   margin-left: 30px; /* LTR */
   width: 26.5em;
 }
-[dir="rtl"] #preview-content {
+[dir="rtl"] .color-preview-content {
   margin-left: 0;
   margin-right: 30px;
 }
-#preview-sidebar .preview-block {
+.color-preview-sidebar .preview-block {
   border: 1px solid;
   margin: 20px 0;
   padding: 15px 20px;
 }
-#preview-sidebar h2 {
+.color-preview-sidebar h2 {
   border-bottom: 1px solid #d6d6d6;
   font-size: 1.071em;
   font-weight: normal;
@@ -110,62 +110,62 @@
   padding-bottom: 5px;
   text-shadow: 0 1px 0 #fff;
 }
-#preview .preview-block .preview-content {
+.color-preview .preview-block .preview-content {
   margin-top: 1em;
 }
-#preview .preview-block-menu .preview-content,
-#preview .preview-block-menu .preview-content ul {
+.color-preview .preview-block-menu .preview-content,
+.color-preview .preview-block-menu .preview-content ul {
   margin-top: 0;
 }
-#preview-main {
+.color-preview-main {
   margin-bottom: 40px;
   margin-top: 20px;
 }
-#preview-page-title {
+.color-preview-page-title {
   font-size: 2em;
   font-weight: normal;
   line-height: 1;
   margin: 1em 0 0.5em;
 }
-#preview-footer-wrapper {
+.color-preview-footer-wrapper {
   color: #c0c0c0;
   color: rgba(255, 255, 255, 0.65);
   display: block !important;
   font-size: 0.857em;
   padding: 20px 20px 25px;
 }
-#preview-footer-wrapper a {
+.color-preview-footer-wrapper a {
   color: #fcfcfc;
   color: rgba(255, 255, 255, 0.8);
 }
-#preview-footer-wrapper a:hover,
-#preview-footer-wrapper a:focus {
+.color-preview-footer-wrapper a:hover,
+.color-preview-footer-wrapper a:focus {
   color: #fefefe;
   color: rgba(255, 255, 255, 0.95);
   text-decoration: underline;
 }
-#preview-footer-wrapper .preview-footer-column {
+.color-preview-footer-wrapper .preview-footer-column {
   display: inline;
   float: left; /* LTR */
   padding: 0 10px;
   position: relative;
   width: 220px;
 }
-[dir="rtl"] #preview-footer-wrapper .preview-footer-column {
+[dir="rtl"] .color-preview-footer-wrapper .preview-footer-column {
   float: right;
 }
-#preview-footer-wrapper .preview-block {
+.color-preview-footer-wrapper .preview-block {
   border: 1px solid #444;
   border-color: rgba(255, 255, 255, 0.1);
   margin: 20px 0;
   padding: 10px;
 }
-#preview-footer-columns .preview-block-menu {
+.color-preview-footer-columns .preview-block-menu {
   border: none;
   margin: 0;
   padding: 0;
 }
-#preview-footer-columns h2 {
+.color-preview-footer-columns h2 {
   border-bottom: 1px solid #555;
   border-color: rgba(255, 255, 255, 0.15);
   font-size: 1em;
@@ -173,24 +173,24 @@
   padding-bottom: 3px;
   text-transform: uppercase;
 }
-#preview-footer-columns .preview-content {
+.color-preview-footer-columns .preview-content {
   margin-top: 0;
 }
-#preview-footer-columns .preview-content ul {
+.color-preview-footer-columns .preview-content ul {
   margin-left: 0; /* LTR */
   padding-left: 0; /* LTR */
 }
-[dir="rtl"] #preview-footer-columns .preview-content ul {
+[dir="rtl"] .color-preview-footer-columns .preview-content ul {
   margin-right: 0;
   padding-right: 0;
 }
-#preview-footer-columns .preview-content li {
+.color-preview-footer-columns .preview-content li {
   list-style: none;
   list-style-image: none;
   margin: 0;
   padding: 0;
 }
-#preview-footer-columns .preview-content li a {
+.color-preview-footer-columns .preview-content li a {
   border-bottom: 1px solid #555;
   border-color: rgba(255, 255, 255, 0.15);
   display: block;
@@ -198,12 +198,12 @@
   padding: 0.8em 2px 0.8em 20px; /* LTR */
   text-indent: -15px;
 }
-[dir="rtl"] #preview-footer-columns .preview-content li a {
+[dir="rtl"] .color-preview-footer-columns .preview-content li a {
   padding-left: 2px;
   padding-right: 20px;
 }
-#preview-footer-columns .preview-content li a:hover,
-#preview-footer-columns .preview-content li a:focus {
+.color-preview-footer-columns .preview-content li a:hover,
+.color-preview-footer-columns .preview-content li a:focus {
   background-color: #1f1f21;
   background-color: rgba(255, 255, 255, 0.05);
   text-decoration: none;
diff --git a/core/themes/bartik/color/preview.html b/core/themes/bartik/color/preview.html
index 3960039..7031b08 100644
--- a/core/themes/bartik/color/preview.html
+++ b/core/themes/bartik/color/preview.html
@@ -1,10 +1,10 @@
-<div id="preview">
+<div class="color-preview">
 
-  <div id="preview-header">
-    <div id="preview-logo"><img src="../../../core/themes/bartik/logo.svg" alt="Site Logo" /></div>
-    <div id="preview-site-name">Bartik</div>
-    <div id="preview-main-menu">
-      <ul id="preview-main-menu-links">
+  <div class="color-preview-header">
+    <div class="color-preview-logo"><img src="../../../core/themes/bartik/logo.svg" alt="Site Logo" /></div>
+    <div class="color-preview-site-name">Bartik</div>
+    <div class="color-preview-main-menu">
+      <ul class="color-preview-main-menu-links">
         <li><a>Home</a></li>
         <li><a>Te Quidne</a></li>
         <li><a>Vel Torqueo Quae Erat</a></li>
@@ -12,9 +12,9 @@
     </div>
   </div>
 
-  <div id="preview-main" class="clearfix">
-    <div id="preview-sidebar">
-      <div id="preview-block" class="preview-block">
+  <div class="color-preview-main clearfix">
+    <div class="color-preview-sidebar">
+      <div class="color-preview-block preview-block">
         <h2>Etiam est risus</h2>
         <div class="preview-content">
           Maecenas id porttitor Ut enim ad minim veniam, quis nostrudfelis.
@@ -22,9 +22,9 @@
         </div>
       </div>
     </div>
-    <div id="preview-content">
-      <h1 id="preview-page-title">Lorem ipsum dolor</h1>
-      <div id="preview-node">
+    <div class="color-preview-content">
+      <h1 class="color-preview-page-title">Lorem ipsum dolor</h1>
+      <div class="color-preview-node">
         <div class="preview-content">
           Sit amet, <a>consectetur adipisicing elit</a>, sed do eiusmod tempor
           incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis
@@ -35,8 +35,8 @@ <h1 id="preview-page-title">Lorem ipsum dolor</h1>
     </div>
   </div>
 
-  <div id="preview-footer-wrapper">
-    <div id="preview-footer-columns" class="clearfix">
+  <div class="color-preview-footer-wrapper">
+    <div class="color-preview-footer-columns clearfix">
       <div class="preview-footer-column">
         <div class="preview-block">
           <h2>Etiam est risus</h2>
diff --git a/core/themes/bartik/color/preview.js b/core/themes/bartik/color/preview.js
index b9fb4d1..7520f29 100644
--- a/core/themes/bartik/color/preview.js
+++ b/core/themes/bartik/color/preview.js
@@ -11,35 +11,35 @@
     callback: function (context, settings, form, farb, height, width) {
       // Change the logo to be the real one.
       if (!this.logoChanged) {
-        $('#preview #preview-logo img').attr('src', drupalSettings.color.logo);
+        $('.color-preview .color-preview-logo img').attr('src', drupalSettings.color.logo);
         this.logoChanged = true;
       }
       // Remove the logo if the setting is toggled off.
       if (drupalSettings.color.logo === null) {
-        $('div').remove('#preview-logo');
+        $('div').remove('.color-preview-logo');
       }
 
       // Solid background.
-      form.find('#preview').css('backgroundColor', $('#palette input[name="palette[bg]"]').val());
+      form.find('.color-preview').css('backgroundColor', $('.js-color-palette input[name="palette[bg]"]').val());
 
       // Text preview.
-      form.find('#preview #preview-main h2, #preview .preview-content').css('color', form.find('#palette input[name="palette[text]"]').val());
-      form.find('#preview #preview-content a').css('color', form.find('#palette input[name="palette[link]"]').val());
+      form.find('.color-preview .color-preview-main h2, .color-preview .preview-content').css('color', form.find('.js-color-palette input[name="palette[text]"]').val());
+      form.find('.color-preview .color-preview-content a').css('color', form.find('.js-color-palette input[name="palette[link]"]').val());
 
       // Sidebar block.
-      form.find('#preview #preview-sidebar #preview-block').css('background-color', form.find('#palette input[name="palette[sidebar]"]').val());
-      form.find('#preview #preview-sidebar #preview-block').css('border-color', form.find('#palette input[name="palette[sidebarborders]"]').val());
+      form.find('.color-preview .color-preview-sidebar .color-preview-block').css('background-color', form.find('.js-color-palette input[name="palette[sidebar]"]').val());
+      form.find('.color-preview .color-preview-sidebar .color-preview-block').css('border-color', form.find('.js-color-palette input[name="palette[sidebarborders]"]').val());
 
       // Footer wrapper background.
-      form.find('#preview #preview-footer-wrapper', form).css('background-color', form.find('#palette input[name="palette[footer]"]').val());
+      form.find('.color-preview .color-preview-footer-wrapper', form).css('background-color', form.find('.js-color-palette input[name="palette[footer]"]').val());
 
       // CSS3 Gradients.
-      var gradient_start = form.find('#palette input[name="palette[top]"]').val();
-      var gradient_end = form.find('#palette input[name="palette[bottom]"]').val();
+      var gradient_start = form.find('.js-color-palette input[name="palette[top]"]').val();
+      var gradient_end = form.find('.js-color-palette input[name="palette[bottom]"]').val();
 
-      form.find('#preview #preview-header').attr('style', "background-color: " + gradient_start + "; background-image: -webkit-gradient(linear, 0% 0%, 0% 100%, from(" + gradient_start + "), to(" + gradient_end + ")); background-image: -moz-linear-gradient(-90deg, " + gradient_start + ", " + gradient_end + ");");
+      form.find('.color-preview .color-preview-header').attr('style', "background-color: " + gradient_start + "; background-image: -webkit-gradient(linear, 0% 0%, 0% 100%, from(" + gradient_start + "), to(" + gradient_end + ")); background-image: -moz-linear-gradient(-90deg, " + gradient_start + ", " + gradient_end + ");");
 
-      form.find('#preview #preview-site-name').css('color', form.find('#palette input[name="palette[titleslogan]"]').val());
+      form.find('.color-preview .color-preview-site-name').css('color', form.find('.js-color-palette input[name="palette[titleslogan]"]').val());
     }
   };
 })(jQuery, Drupal, drupalSettings);
diff --git a/core/themes/bartik/css/colors.css b/core/themes/bartik/css/colors.css
index 8443b53..a0ce6c0 100644
--- a/core/themes/bartik/css/colors.css
+++ b/core/themes/bartik/css/colors.css
@@ -56,14 +56,14 @@ a:active,
 
 /* ---------- Color Form ----------- */
 
-[dir="rtl"] .color-form #palette {
+[dir="rtl"] .color-form .js-color-palette {
   margin-left: 0;
   margin-right: 20px;
 }
 [dir="rtl"] .color-form .form-item label {
   float: right;
 }
-[dir="rtl"] .color-form #palette .lock {
+[dir="rtl"] .color-form .js-color-palette .lock {
   right: -20px;
   left: 0;
 }