I agree with the above comments. You have set manual white balance to flash. Ordinarily that's a safe practice, but in this case I suspect some contamination from light coming off the walls. They're a bit orange, and it's also possible that there is some contribution from incandescent lamps - it's hard to tell the difference from here as the results will be similar.
Either of these is a little difficult to address in the field, as you're essentially working with mixed colors of light: direct flash is more or less daylight, and either incandescent or flash off those orange walls will be much redder.
I am suspicious that you also bounced the flash, probably almost directly up, since most of the flash shadow is very subtle. It's not gone, though - Santa's cap projects a hard-edged shadow. Or perhaps that shadow is coming from some other light source. Either way, with bounce flash you are almost certainly getting some spillage from the walls, perhaps quite a bit.
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!