Is referring to a person of African decent as “black” racist?

So

I was playing video games with a friend of mine and he asked me which character I like to play.

Since I just started playing this game (valorant) I didn’t know the names of the characters and referred to them as “the white guy” (Sova) and “the black guy” (Phoenix) and when I said “the black guy” he gasped in shock and said that it is a bit racist to say that....I have since learned their names so this doesn’t happen again

We kinda had a discussion about whether or not what I said was racist or not and we never came to a conclusion...

So if anyone knows can you please tell me if this is some micro aggression I need to fix? I honestly don’t know if I was being racist or not

Thank you everyone