‘Lumos GUI ’ is your next design kit, that is a perfect solution to designing a graphical user interface.
Included in the download is a .psd file that is clearly labelled and grouped into each element. A .pdf help file is also included to get you started.
The file is easy to edit and customize to suit your needs. Changing the colours is very simple, by editing the colour / gradient overlay on each layer style. An example of how to do this is described in the help file.