- when you shoot with flash, in mixed lighting, you can get, very often, not the best, or consistent, White Balance
- as such, you have to be ready to individually WB each picture if necessary
- I would suggest that you play with the WB to get a slightly warmer less bluish image
- there is also funky green / magenta stuff going on in this image which might be harder to correct
I don't see a 'flashed' looked to his face, nor a strong flashed catch light, so I'm guessing you either bounced the flash or might have cropped this image. One of, if not the biggest issue with flash, is getting the WB correct in mixed lighting environments - and once the mixed lighting has been 'mixed' it really can't be unmixed - so maybe think of practicing with gelling your flashes in the future or try and work on your Post Processing and getting the WB 'better'.
Yes tried to use a bounced flash. I had some issues with trying to figure out the white balance in UFRAw to find one I was happy with. In the end I went with automatic which probably was a misstake (UFRaws predefined flash setting turned the image very blue indeed)