Femme Fatale

Y’all. What kind of shirt would you wear under this exact blazer?

I am wearing it to an office Christmas party on Friday (not my office). Mine is sized up, so it fits oversized, and I’m rolling the sleeves up. Is a baggy black tank top too plain? I have a black sequined tank, but I think the sequins are too much. I just don’t know what fucking color to wear with cream and black. Help?