Sosa hit up DuJour's Miami Beach's Art Basel Kick-Off at The Confidante where he posed for pics on his way into the event ... weeks after T.I. blasted him for his alleged skin bleaching.

Sammy's complexion has very obviously changed over the years. We can only find one interview where he addressed it -- from 2009 -- saying the lightening was an unexpected result of a skin softening cream.

T.I. called B.S. and said it was more about "self-hate" -- but, judging by the way Sammy was smiling and laughing on the red carpet, he really doesn't seem to care what anyone else thinks.