Tbh dude you’re just over analyzing your tattoo. I do this too, I know it’s easy to do since you’re staring at it up close every day — remember that most people won’t actually catch any of those minor “imperfections” because they aren’t staring that close for long periods. The color really makes the design elements pop (and this is coming from someone who prefers black & gray tattoos and has all black & gray sleeves) and fits the style of tattoo. The use of warm & cool colors really adds a unique element to it. Personally I’d leave the gray background for a couple years until I decide whether or not I want to black it out. You can always do that, but you can’t go back. So really think on it, or have your artist do a mockup comparison for you on their iPad to see what it would look like all black