I endorse black with color, and that's because magenta and cyan and blue and red floating in blackness reminds me of a BBS.
I was considering banning white altogether, but I find it necessary for the task bar and clock font. I scraped a program I was playing with, that changed the lxpanel font color in relation to my remaining battery charge, partially because I couldn't take non-white colors for font.
I like stark, simple icons, no shading or even outlines, so while I use colorful icons, they tend to be super simple, of a single color, and low resolution. Which to me makes them more minimal than some grayscale stuff.