I also always thought it was "suit of lies" which I think makes more sense.
But in U2 by U2 Bono says,
"Gone is a portrait of a young man as a rock star, trying to cut himself free from responsibilities and just enjoy the ride, the suit of lights, fame."
Then he says (to paraphrase) that the man tries to leave behind those responsibilities but "there are some things you can't leave behind." and "deep down we aren't as shallow as we'd like."
I suppose the song is about realizing the shallowness of fame and embracing your responsibilities. This makes sense if you think about the transition from the POP album (and really all of the '90s material) to the ALL THAT YOU CAN'T LEAVE BEHIND album.