I couldn't find any good hires and perfectly aligned UV patterns on the web so I made my own.

This is a 4096*4096 PSD file and has all the square layers set up with masks so you can easily change the gradient or add new colours. The type is set up as a smart object which you can open and change the font or lettering, although I don't recommend changing the lettering as it takes ages to type up 512 letters ;)