I researched painting formica once before. I had formica wall cabnets that had a 70's motif to them. After much researched I learned the best and safest way to paint them is with epoxy Bath and Tub paitn the can be purchased at Home Depot. It can be brushed on and is self leveling. The only problem for you is that it comes in white, beig and grey, but not a granite looking color.