diff --git a/bundles/org.eclipse.ui.themes/css/e4_preview_gtk.css b/bundles/org.eclipse.ui.themes/css/e4_preview_gtk.css
index af47d971118..c8dd132df1d 100644
--- a/bundles/org.eclipse.ui.themes/css/e4_preview_gtk.css
+++ b/bundles/org.eclipse.ui.themes/css/e4_preview_gtk.css
@@ -126,11 +126,11 @@ CTabFolder Canvas {
 }
 
 .MTrimBar#org-eclipse-ui-main-toolbar {
-	background-color: '#f8f8f8';
+	background-color: #f8f8f8;
 }
 
 .MTrimBar#org-eclipse-ui-trim-status {
-	background-color: '#f8f8f8';
+	background-color: #f8f8f8;
 }
 
 .View Composite,
@@ -197,14 +197,14 @@ CTabFolder Canvas {
 
 /* text color and background color of unselected tabs in editor*/
 #org-eclipse-ui-editorss CTabItem{
-	color: '#000000';
-	background-color: '#f8f8f8';
+	color: #000000;
+	background-color: #f8f8f8;
 }
 
 /*text color and background color of selected tab in editor */
 #org-eclipse-ui-editorss CTabItem:selected{
-	color: '#000000';
-	background-color: '#FFFFFF';
+	color: #000000;
+	background-color: #FFFFFF;
 }
 
 #org-eclipse-ui-editorss CTabFolder{
@@ -218,7 +218,7 @@ CTabFolder Canvas {
 }
 
 #org-eclipse-ui-editorss CTabFolder.active {
-	swt-selected-tab-highlight: '#2160bb';
+	swt-selected-tab-highlight: #2160bb;
 	swt-selected-highlight-top: true;
 }
 
diff --git a/bundles/org.eclipse.ui.themes/css/e4_preview_mac.css b/bundles/org.eclipse.ui.themes/css/e4_preview_mac.css
index 775ff4d8c29..3a869957874 100644
--- a/bundles/org.eclipse.ui.themes/css/e4_preview_mac.css
+++ b/bundles/org.eclipse.ui.themes/css/e4_preview_mac.css
@@ -83,15 +83,15 @@ ColorDefinition#org-eclipse-ui-workbench-INACTIVE_TAB_TEXT_COLOR {
 }
 
 .MTrimmedWindow {
-	background-color: '#f8f8f8';
+	background-color: #f8f8f8;
 }
 
 .MTrimBar {
-	background-color: '#f8f8f8';
+	background-color: #f8f8f8;
 }
 
 .MTrimBar#org-eclipse-ui-main-toolbar {
-	background-color: '#f8f8f8';
+	background-color: #f8f8f8;
 }
 
 CTabFolder Canvas {
@@ -100,7 +100,7 @@ CTabFolder Canvas {
 
  
 .MTrimBar#org-eclipse-ui-trim-status {
-	background-color: '#f8f8f8';
+	background-color: #f8f8f8;
 }
 
 .View Composite,
@@ -167,14 +167,14 @@ CTabFolder Canvas {
 
 /* text color of unselected tabs in editor*/
 #org-eclipse-ui-editorss CTabItem{
-	color: '#000000';
-	background-color: '#f8f8f8';
+	color: #000000;
+	background-color: #f8f8f8;
 }
 
 /*text color and background color of selected tab in editor */
 #org-eclipse-ui-editorss CTabItem:selected{
-	color: '#000000';
-	background-color: '#FFFFFF';
+	color: #000000;
+	background-color: #FFFFFF;
 }
 
 #org-eclipse-ui-editorss CTabFolder{
@@ -188,7 +188,7 @@ CTabFolder Canvas {
 }
 
 #org-eclipse-ui-editorss CTabFolder.active {
-	swt-selected-tab-highlight: '#5983c5';
+	swt-selected-tab-highlight: #5983c5;
 	swt-selected-highlight-top: true;
 }
 
diff --git a/bundles/org.eclipse.ui.themes/css/e4_preview_win.css b/bundles/org.eclipse.ui.themes/css/e4_preview_win.css
index b9357320503..713844c0a8d 100644
--- a/bundles/org.eclipse.ui.themes/css/e4_preview_win.css
+++ b/bundles/org.eclipse.ui.themes/css/e4_preview_win.css
@@ -100,11 +100,11 @@ CTabFolder Canvas {
 }
 
 .MTrimBar#org-eclipse-ui-main-toolbar {
-	background-color: '#f8f8f8';
+	background-color: #f8f8f8;
 }
 
 .MTrimBar#org-eclipse-ui-trim-status {
-	background-color: '#f8f8f8';
+	background-color: #f8f8f8;
 }
 
 .View Composite,
@@ -171,14 +171,14 @@ CTabFolder Canvas {
 
 /* text color and background color of unselected tabs in editor*/
 #org-eclipse-ui-editorss CTabItem{
-	color: '#000000';
-	background-color: '#f8f8f8';
+	color: #000000;
+	background-color: #f8f8f8;
 }
 
 /*text color and background color of selected tab in editor */
 #org-eclipse-ui-editorss CTabItem:selected{
-	color: '#000000';
-	background-color: '#FFFFFF';
+	color: #000000;
+	background-color: #FFFFFF;
 }
 
 #org-eclipse-ui-editorss CTabFolder{
@@ -192,7 +192,7 @@ CTabFolder Canvas {
 }
 
 #org-eclipse-ui-editorss CTabFolder.active {
-	swt-selected-tab-highlight: '#2160bb';
+	swt-selected-tab-highlight: #2160bb;
 	swt-selected-highlight-top: true;
 }