Dyeing Embossed Leathers Like Gator And Ostrich?

[IngleGunLeather]

I recently bought myself a stainless Colt Commander and I am wanting do up a real nice avenger style holster with embossed gator or ostrich skin. I want go to with grey and black. Up to this point all I've done is solid coloring. The picture of the seat below is the look I'm trying to achieve. However, I want grey and black vice brown and black. Would this be achieved by solid dying the grey first, then block dyeing with black?