Box-sizing border box on the page makes your colorpicker too small
![image](https://cloud.githubusercontent.com/assets/548027/9700352/9c309af4-53cd-11e5-97d4-9c396609fae3.png)

box-sizing set to border box on the page is clashing with your css
you should set box-sizing on the element to whatever you want as part of your element css
