diff --git a/node_modules/ace_tree/lib/ace_tree/css/light_theme.css b/node_modules/ace_tree/lib/ace_tree/css/light_theme.css
index 4f1a00fa..e4b3e5aa 100644
--- a/node_modules/ace_tree/lib/ace_tree/css/light_theme.css
+++ b/node_modules/ace_tree/lib/ace_tree/css/light_theme.css
@@ -14,15 +14,6 @@
     overflow: visible;
     width: 10px;
     height: 10px;
-    background-image: url(data:image/png;base64,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);
-    background-repeat: no-repeat;
-    background-position: 0px 0px;
-    background-repeat: no-repeat;
-}
-
-
-.ace_tree-light {
-    background-image: url("data:image/png;base64,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");
 }
 
 .ace_tree-light .tree-row .caption {
@@ -46,9 +37,6 @@
 }
 
 .ace_tree_focus.ace_tree-light .tree-row.selected {
-    border-top: 1px solid #3A9BEC;
-    border-bottom: 1px solid #185F97;
-    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#1f82d2', endColorstr='#2890e5');
     background: -webkit-gradient(linear, left top, left bottom, from(#2890E5), color-stop(1, #1F82D2));
     background: -moz-linear-gradient(center bottom, #1f82d2 0%, #2890e5 100%) repeat scroll 0 0 transparent;
     background: linear-gradient(center bottom, #1f82d2 0%, #2890e5 100%) repeat scroll 0 0 transparent;
@@ -85,6 +73,3 @@
     margin-left: -1px;
     border-left: 1px solid rgba(0, 0, 0, 0);
 }
-
-
-
diff --git a/plugins/c9.ide.ui/widgets.less b/plugins/c9.ide.ui/widgets.less
new file mode 100644
index 00000000..4283f1c4
--- /dev/null
+++ b/plugins/c9.ide.ui/widgets.less
@@ -0,0 +1,156 @@
+.custom-tree.ace_tree {
+    background: transparent;
+    border: none;
+    font: 11px Tahoma, Arial;
+    .font-smoothing(@tree-font-smoothing)
+}
+
+.custom-tree.ace_tree .tree-row {
+    background : transparent;
+    color : @color;
+    border-radius: 3px;
+    margin: 1px 0px 0px 0px;
+    padding-left: 6px;
+    height: @tree-row-height;
+}
+.custom-tree.ace_tree.list .tree-row {
+    margin: 1px 0px 0px 0px;
+    padding-left: 0;
+}
+
+.custom-tree.ace_tree .tree-row.selected {
+    background: @selected-background;
+    border-color: transparent;
+    color : @selected-color;
+}
+
+.custom-tree.ace_tree_focus .tree-row.selected {
+    background: @selected-focus-background;
+    color: @selected-focus-color;
+}
+
+.custom-tree.ace_tree .message {
+    border : 0;
+    padding : 3px;
+    text-align : center;
+    background : transparent;
+    font-size: 11px;
+    
+    margin: 20px 10px 0 10px;
+    word-wrap: break-word;
+    white-space: normal;
+    color: #BBB;
+    line-height: 1.5em;
+}
+
+.custom-tree.ace_tree .tree-row .toggler{
+    .image-2x("@{tree-arrow}", 20px, 10px);
+    margin: 0 1px 0 0;
+}
+
+.custom-tree.ace_tree_focus .tree-row.selected .toggler{
+    .image-2x("@{tree-arrow-focus-selected}", 20px, 10px);
+}
+
+.custom-tree.ace_tree .tree-row > span {    
+    vertical-align: middle;
+    padding: @tree-row-padding;
+    line-height: 20px;
+    display: inline-block;
+}
+
+.custom-tree.ace_tree-icon {
+    width: 16px;
+    height: 16px;
+    padding: 0px;
+    margin: 0px 1px;
+    background-repeat: no-repeat;
+}
+
+.loading .ace_tree-icon,
+.loading-icon {
+    .image-2x("@{tree-spinner}", @tree-spinner-width, @tree-spinner-height);
+}
+
+.loading.selected .ace_tree-icon,
+.selected .loading-icon {
+    .image-2x("@{tree-focus-spinner}", @tree-spinner-width, @tree-spinner-height);
+}
+        
+.custom-tree.ace_tree_focus .loading.selected .ace_tree-icon,
+.custom-tree.ace_tree_focus .selected .loading-icon {
+    .image-2x("@{tree-selected-focus-spinner}", @tree-spinner-width, @tree-spinner-height);
+}
+
+.tree-row.dragAppendUpload -icon {
+    background-image : url("@{image-path}/@{tree-upload}");
+    background-position: -5px -1px;
+}
+
+.ace_treeDragImage.copy:after {
+    content: "+";
+    background: fade(@selected-focus-background, 92%);
+    border: 1px @selected-focus-background solid;
+    position: absolute;
+    right: -6px;
+    bottom: -6px;
+    color: @selected-focus-color;
+    font-size: 14px;
+    border-radius: 8px;
+    width: 14px;
+    height: 13px;
+    text-align: center;
+    line-height: 13px;
+    font-weight: bold;
+    font-family: monospace;
+    background: -webkit-radial-gradient(5px 5px, circle, rgb(126, 143, 28), rgb(76, 93, 0));
+    background: radial-gradient(5px 5px, circle,  rgb(126, 143, 28), rgb(76, 93, 0));
+    box-shadow: 0px 0px 7px 0px #000;
+}
+.ace_treeDragImage .toggler {
+    pointer-events: none;
+}
+
+.custom-tree.ace_tree_DragOver .tree-row.selected {
+    background: fade(@selected-background, 60%);
+}
+.custom-tree.ace_tree_DragOver .tree-row.dropTarget {
+    background: @selected-focus-background;
+    box-shadow: 1px 1px fade(@selected-focus-background, 60%) inset;
+    color: @selected-color;
+    border-radius: 3px;
+    .box-sizing(border-box);
+    margin-right: 5px;
+}
+
+.dragHighlight {
+    position: absolute;
+    border: solid 1px fade(@selected-focus-background, 60%);    
+    border-right: rgba(0, 0, 0, 0);
+    border-top: rgba(0, 0, 0, 0);
+    background: fade(@selected-focus-background, 10%);
+}
+
+.dragArrow {
+    position: absolute;
+    border: 1px solid @selected-focus-background;
+    margin-top: 2px;
+}
+.dragArrow::before {
+    content:"";
+    background: @selected-focus-background;
+    position: absolute;
+    top: -3px;
+    left: -3px;
+    width: 6px;
+    height: 6px;
+    border-radius: 4px;
+}
+
+.custom-tree.ace_tree-editor {
+    color: @tree-editor-color;
+    background-color: @tree-editor-background;
+    border: 1px solid @tree-editor-border-color;
+    height: @tree-editor-height !important;
+    margin-top: @tree-editor-margin-top !important;
+}
\ No newline at end of file
diff --git a/plugins/c9.ide.ui/widgets.list.js b/plugins/c9.ide.ui/widgets.list.js
index 11590172..2d3c2714 100644
--- a/plugins/c9.ide.ui/widgets.list.js
+++ b/plugins/c9.ide.ui/widgets.list.js
@@ -1,10 +1,11 @@
 define(function(require, exports, module) {
-    main.consumes = ["Plugin"];
+    main.consumes = ["Plugin", "ui"];
     main.provides = ["List"];
     return main;
 
     function main(options, imports, register) {
         var Plugin = imports.Plugin;
+        var ui = imports.ui;
         
         var AceTree = require("ace_tree/tree");
         var AceTreeEditor = require("ace_tree/edit");
@@ -15,6 +16,10 @@ define(function(require, exports, module) {
             return this.emptyMessage || "";
         };
         
+        ui.on("load", function(){
+            ui.insertCss(require("text!./widgets.less"), ui);
+        });
+        
         /***** Constructors *****/
         
         function List(options, forPlugin, baseclass) {
@@ -43,6 +48,10 @@ define(function(require, exports, module) {
                     ? new TreeModel()
                     : new ListModel());
                 
+                // Set Default Theme
+                if (!options.theme)
+                    options.theme = "custom-tree " + (options.baseName || "list");
+                
                 // Set model
                 acetree.setDataProvider(model);