The style is merely simplified re-colouring of the default stock graphics. Download the GDK (graphics development kit) from the members area (you'll need a graphics editor) and you'll be able to overlay the stock graphics with any colour you desire. Same rule goes with the style images (gradients) load them into your graphics editor and choose the colours you desire by either using the hue and saturation, colour balance or other adjustment layers the editor provides.
You may want to look into downloading and installing the
gimp. A free graphics ediotr if you don't happen to have one installed on your system.