My version for ExtJS 4.2.0
since there's often asked about some color picker component, I decided to share what I've done some time ago.
The color class itself and the components can deal with alpha transparent values. Anyway, there's currently no UI to edit it with the color picker, since I didn't need it for now. But it should be easy for you to implement if needed.
Please apologize, that all comments are in German, but really, I will not translate it into English. The documentation already took a lot of time. But I think you can work with anyway.
You can unzip the content into the examples folder and open the html file for an example.