Invalid Commander Deck

[Indestructicon]

I'm kind of new to forums, I hope this is the proper way. On Xmagic I am being told my commander deck has invalid colors, and it is mono black. It says every card is invalid to do color. Even just trying to play the A.I. Does anyone know why this happens? I feel it is just some simple setting or something.

[Indestructicon]

Issue resolved, thank you.

[ortingkm]

How did you resolve issue? My mono red deck is saying the same thing.