diff --git a/src/js/controller/settings/exportimage/GifExportController.js b/src/js/controller/settings/exportimage/GifExportController.js
index d1793b21..ead09a61 100644
--- a/src/js/controller/settings/exportimage/GifExportController.js
+++ b/src/js/controller/settings/exportimage/GifExportController.js
@@ -117,10 +117,10 @@
 
   ns.GifExportController.prototype.renderAsImageDataAnimatedGIF = function(zoom, fps, cb) {
     var currentColors = pskl.app.currentColorsService.computeCurrentColors();
-    
+
     var preserveColors = currentColors.length < MAX_GIF_COLORS;
     var transparentColor = this.getTransparentColor(currentColors);
-    
+
     var gif = new window.GIF({
       workers: 5,
       quality: 1,
@@ -155,17 +155,16 @@
 
   ns.GifExportController.prototype.getTransparentColor = function(currentColors) {
     var transparentColor = pskl.utils.ColorUtils.getUnusedColor(currentColors);
+
     if (!transparentColor) {
       console.error('Unable to find unused color to use as transparent color in the current sprite');
       transparentColor = MAGIC_PINK;
-    } else {
-      transparentColor = window.tinycolor(transparentColor).toHexString();
     }
+
     return transparentColor;
   };
 
-  // FIXME : HORRIBLE COPY/PASTA
-
+  // FIXME : JD : HORRIBLE COPY/PASTA (JD later : where???)
   ns.GifExportController.prototype.updateStatus_ = function (imageUrl, error) {
     if (imageUrl) {
       var linkTpl = "<a class='image-link' href='{{link}}' target='_blank'>{{shortLink}}</a>";
diff --git a/src/js/utils/ColorUtils.js b/src/js/utils/ColorUtils.js
index a1635fe3..34ac60f3 100644
--- a/src/js/utils/ColorUtils.js
+++ b/src/js/utils/ColorUtils.js
@@ -3,25 +3,25 @@
 
   ns.ColorUtils = {
     getUnusedColor : function (usedColors) {
-      // start with white
-      var color = {
-        r : 255,
-        g : 255,
-        b : 255
-      };
-
+      usedColors = usedColors || [];
       // create check map
       var colorMap = {};
       usedColors.forEach(function (color) {
         colorMap[color.toUpperCase()] = true;
       });
 
+      // start with white
+      var color = {
+        r : 255,
+        g : 255,
+        b : 255
+      };
       var match = null;
         while (true) {
           var hex = tinycolor(color).toHexString().toUpperCase();
 
         if (!colorMap[hex]) {
-          match = color;
+          match = hex;
           break;
         } else {
           // pick a non null component to decrease its value
diff --git a/test/js/utils/ColorUtilsTest.js b/test/js/utils/ColorUtilsTest.js
new file mode 100644
index 00000000..bcc68e1c
--- /dev/null
+++ b/test/js/utils/ColorUtilsTest.js
@@ -0,0 +1,29 @@
+describe("Color utils", function() {
+
+  beforeEach(function() {});
+  afterEach(function() {});
+
+  it("returns a color when provided with array of colors", function() {
+    // when/then
+    var unusedColor = pskl.utils.ColorUtils.getUnusedColor(['#ffffff', '#feffff', '#fdffff']);
+    // verify
+    expect(unusedColor).toBe('#FCFFFF');
+
+    // when/then
+    unusedColor = pskl.utils.ColorUtils.getUnusedColor(['#fcffff', '#feffff', '#fdffff']);
+    // verify
+    expect(unusedColor).toBe('#FFFFFF');
+  });
+
+  it("returns a color for an empty array", function() {
+    // when/then
+    var unusedColor = pskl.utils.ColorUtils.getUnusedColor([]);
+    // verify
+    expect(unusedColor).toBe('#FFFFFF');
+
+    // when/then
+    unusedColor = pskl.utils.ColorUtils.getUnusedColor();
+    // verify
+    expect(unusedColor).toBe('#FFFFFF');
+  });
+});
\ No newline at end of file