564         },

   565         // from http://stackoverflow.com/a/6444043

   566         increaseBrightness: function (hex, percent){

   567             // strip the leading # if it's there

   568             hex = hex.replace(/^\s*#|\s*$/g, '');

   569 

   570             // convert 3 char codes --> 6, e.g. `E0F` --> `EE00FF`

   571             if(hex.length === 3){

   572                 hex = hex.replace(/(.)/g, '$1$1');

   573             }

   574 

   575             var r = parseInt(hex.substr(0, 2), 16),

   576                 g = parseInt(hex.substr(2, 2), 16),

   577                 b = parseInt(hex.substr(4, 2), 16);

   578 

   579             return '#' +

   580                ((0|(1<<8) + r + (256 - r) * percent / 100).toString(16)).substr(1) +

   581                ((0|(1<<8) + g + (256 - g) * percent / 100).toString(16)).substr(1) +

   582                ((0|(1<<8) + b + (256 - b) * percent / 100).toString(16)).substr(1);