I know this is supposed to be meaningful, but seriously, wouldn't it be cool if we could do that? Cry in 7 different colors? NO! Better yet, bleed rainbow blood, now THAT would be trippy! True, it'd blow our cover at the blood bank, but still.
There is a beautiful and very sad song called Rainbow Eyes which was done by the band Rainbow when Ronnie James Dio was with them. Dio also performed the song solo. I don't know if you might be familiar with the tune, but this picture makes me think of it!