I like to wear black hose with my formal outfit, mainly because of the black jacket. I don't really like the off white hose in a formal look, although if you wear the ghillie brogues it does set off the laces really well.

I will sometimes wear black hose in less than formal setting, but usually only with my MacIan tartan kilt which has a fair amount of black in it. And even then, only if I am also wearing a black sweater or jacket as well.

The main thing is to coordinate the color with the rest of your outfit.