No, I can't help you with templates, but I HAVE sprayed my saturn a different colour (it is now purple, with a yellow Sailor Saturn logo on the lid). Hmm, just draw down the sides you are going to put detail on then draw the detail on them, my friend has a marble saturn (it's a mix of white and faded purple, swirling and splated all over, it's really cool).
Now for a question myself, does anyone know what plastic is most recommended for designing your own case completely (I want it to look like the prototype Playstation 2)