I use gray scale for my comic.
At first my characters didn't have a skin tone to seperate them from the BG, so they are looking a little pale in the first two chapters.
But as far as coloring, I use varying grays with a opacity brush for backgrounds. While using a cell shade approach to ppl and objects. I also use solid blacks.
Images below from Ch2
Now I'm going with a different color approach to skin tones, and I have been looking at two comics that also do these treatment.
My treatment in upcoming ch3:
^^^
With this "new" approach, white is a distinct color as it should be... so it stands out on a skin tone.
I think looking at how other comics are addressing skin tones and backgrounds will help you in deciding the best approach!
Here are some excellent comics with difference approaches to coloring gray-scale:
Ember Cross
Void Child
Easy
Legio Arcana
As someone else said, just see what works best for you! It took me a while to stumble upon what I am doing now