Wow Hendo, those are really awesome! My eyes are drawn instantly to the rainbow ones; they're incredibly pleasant to look at. Here's hoping you'll post a tutorial one day!
I did this green one last night:
The background looks kinda grainy to me and the text doesn't sit properly on it, but I did it in fifteen minutes whilst eating supper, (a peanut butter and
honey sandwich; try it, it's delicious) so I suppose I shouldn't really expect any better. I'll try the red and blue one next.