It is really hard to tell from the pictures. it looks like the outer rim is just brown but I can see small parts of die off that maybe look like where it was handled. This particular chalice I remember being especially delicate and easily broken. Handling, fish checking out the new big thing in the tank both could have easily damaged it.
I would expect it to change color from going from MH to a different lighting scheme, surprisingly many LPS are lower light corals. Don't let their super bright colors fool you!
Dipping LPS can be a bit stressful and they form so much slime you may or may not do more harm than good. If you have to dip I'd recommend pH balanced Ro/di with a few drops of iodine just in case there is anything bothering it but without a better picture I don't really see anything wrong. Was the chalice not colored this way in your friends tank? I'd really see how it looks after a month or so, it could just be an explosion of zooxanthellae adjusting to the light?