Durability has nothing to do with color vs black and gray. Durability depends on your skin, how you take care of your tattoos (stay out of the sun and moisturize), skill of your tattooer. 

why do you say that color tattoos are not as durable ? if a tattoo is applied properly it doesn't matter if it's black & gray or color, it all lasts the same. I have color tattoos that are brighter and more vibrant than some of my B&G pieces ,and that's after years of healing on all.

that's what my sister did.