My recently finished DMR is a rainbow of colors (cold cast nickel, dark gray, ivory and light gray) the paint job I've given it does a fantastic job of hiding it. I also used Krylon clear coat gloss to protect the paint, and surprisingly it's pretty good at resisting scratchs. Despite the DMR being a cold cast, I still dry brushed silver on it. Also, putting dyes in resin to make it black or gray or neon green, that's an extra step in the process, which I don't like extra steps with my projects.
So for me, no it doesn't make much of a difference, and I'll stick with my sickly yellow resin color. Nice 'nades BTW, may need to get me some...