Fix default color check in palette

www/drive/app-drive.less

@@ -207,13 +207,17 @@
                     position: absolute;
                     top: -1px; left: 0;
                     width: 200%;
-                    border: 1px solid #666;
+                    border: 1px solid #bbb;
                     transform-origin: top left;
                     -ms-transform-origin: top left;
                     transform: rotate(45deg);
                     -ms-transform: rotate(45deg);
                     -webkit-transform: rotate(45deg);
                 }
+                &.cp-app-drive-current-color > .fa-check {
+                    top: 35%; left: 35%;
+                    color: black;
+                }
             }
 
             .cp-app-drive-icon-folder {

www/drive/inner.js

@@ -876,8 +876,17 @@ define([
 
                 var element;
                 if (i === 0) {
-                    element = h("span.cp-app-drive-color-picker-color.cp-app-drive-no-color");
+                    element = h("span.cp-app-drive-color-picker-color.cp-app-drive-no-color", [
+                        h("span.fa.fa-check")
+                    ]);
+                    if (currentColor === "") {
+                        currentElement = element;
+                        $(element).addClass("cp-app-drive-current-color");
+                    }
                     $(element).on("click", function () {
+                        $(currentElement).removeClass("cp-app-drive-current-color");
+                        currentElement = element;
+                        $(element).addClass("cp-app-drive-current-color");
                         cb("");
                     });
                     colorsElements.push(element);
@@ -907,7 +916,7 @@ define([
 
         var getFolderColor = function (path) {
             if (path.length === 0) { return; }
-            return manager.getFolderData(path).color || "#000";
+            return manager.getFolderData(path).color || "";
         };
 
         var setFolderColor = function ($element, path, color) {