I think it's more of personal preference; but as an artist, it's always good to push yourself.
It also depends on the style of your comic. I looked at yours, and it could go either way. If you have extra time, though, I suggest blocking in some base colors to see what works. Keep in mind that only doing grey-tones can get a little boring sometimes, so it's nice to switch things up and experiment.
Either way, your art looks great! Keep it up! ^_^