Fix a graphical bug in Firefox

Author: yannickcr

public/js/lib/models/arrow.js

@@ -36,6 +36,22 @@ if (!('CSSArrowPlease' in window)) window.CSSArrowPlease = {};
       else if ( pos === 'right' ) return 'left';
     },
 
+    /**
+    @method hexToRGB
+    @description 
+      returns an rgb color from an hex color
+    @returns {Array}
+    **/
+    hexToRGB: function (h) {
+      var rgb = [],
+          i = 1;
+
+      for(; i < 6; i+=2) {
+        rgb.push(parseInt(h.substring(i, i + 2), 16));
+      }
+      return rgb;
+    },
+
     /**
     @method _baseCSS
     @description generates the base css
@@ -87,12 +103,14 @@ if (!('CSSArrowPlease' in window)) window.CSSArrowPlease = {};
     _arrowCSS: function (color, size, layer) {
       var pos       = this.get('position'),
           iPos      = this.invertedPosition(),
+          rgbColor  = this.hexToRGB(color),
           css       = ".arrow_box:";
 
       layer = layer || 'after';
 
       css += layer + ' {\n';
 
+      css += '\tborder-color: rgba(' + rgbColor.join(', ') + ', 0);\n';
       css += '\tborder-' + iPos + '-color: ' + color + ';\n';
       css += '\tborder-width: ' + size + 'px;\n';