It's the light colors that I would avoid, since coffee is dark and oily. Some may say that lighter is better so that you can see where all of the coffee and oil is. As a person who gives my machine a wipe-down to keep it clean after every use, I am really glad it is not light colored.
This was one of the things that floored me when the Niche grinder effort started and they only offered white ... probably the absolute worst color for coffee workings, especially for a coffee grinder.
LMWDP #581 .......... May your roasts, grinds, and pulls be the best!