Alec Baldwin Tells Fan 'Stay Black'

Alec Baldwin kept it 100 with a fan in NYC, posing for a pic and telling him, "Stay black" ... which we're guessing he will ... 'cause he's African-American.

Chill. Watch the video. The guy knows Alec, he's a big time autograph seeker in NYC ... and uses #StayBlack on his social media. Totally friendly exchange.