its actually pritty easy to do, ive not tried it on evos yet but ive done a couple of revvis and a halo
revvies are easy but halos and evos are made of different plastic so it might work differently
i wont give his secret away but Leigh is using a differnt type of dye on his to what i have seen used before and the evos he has done look great, ive seen his pink one and also a light blue one.
im sure if you contact him on here he will hook you up or do one for you etc......im not sure if he is charging to do em or what not or how much but it dont hurt to ask.
ill try my method on an egg shell when i get a spare hour and see what it comes out like