It might be a good starting point, though. Sluggy Freelance didn't have color. Many newspaper strips probably don't have color. Maybe he can do color Sundays, or at some point, put in some shading. But line-art isn't terrible if he can do it right. Maybe he can do some cross hatching and those sorts of terms. Not a big artist. Like to draw though.
You should start the comic though. I'm sure you'll figure it out. Do you need to draw African-Americans immediately?
In any case, art is only part of what makes a comic. Focus on your story too, probably. And while you're doing your strip and evolving your style, sketch ideas on how to present African-Americans. Do they have Afros or Dreadlocks or different facial structures? Do they dress differently? Do they have certain personalities? I don't mean stereotype, but I understand they have distinct cultures too, like other groups of people.
Is it about African-Americans though? And if so, is it because you relate with them? If you do, maybe you can draw from what you know. Or study how other people draw them.
It's not always about color.