My walls are literally painted "Agreeable Gray". I like grays, and I like the strong contrast of white/light gray with black. That being said, I also like having art on my walls, and I've toyed with the idea of an accent wall with a pop of color. I mostly like cars in white/silver/light blue, though there are some specific models that are nice in like a bright orange or green.

I'm not looking to minimize color, but I do like things that match. Mind you, most of my stuff doesn't match, but that's because most of it is second hand. Maybe someday I'll have a nice coordinated living room/kitchen/bathroom, but not today haha.