[UPDATE BELOW] If you haven't noticed, the Empire State Building hasn't been able to make up its mind about what colors to be for the past few nights. But what does it mean? The Empire State Building's website is not much help, saying the colors should be "Private Lighting," which most likely means they were either testing the lights or a private party requested those colors. We've contacted the building to see what was up, but there are a few other possibilities.
November 20th was the national Transgender Day of Remembrance, celebrated in remembrance of those who were killed from anti-transgender hatred or prejudice. It is also Children's Day, and Absurdity Day, both of which could be represented by a rainbow of color.
In August, hundreds protested over the ESB's refusal to light up blue and white in honor of Mother Teresa, which they said they wouldn't do because they do not honor religious figures with their lights. Though they only figure they'd probably be honoring with these lights is Jerry Garcia, so it could be for the Furthur shows going on at MSG.
[UPDATE] According to this Phish message board, the colorful lights are most definitely for the Furthur shows. One commenter said, "It is definitely for Furthur (not speculation, fact) and it was great last night." We'll take your word for it!