Yeah, I noticed that. Something about FM's rendering. On my monitor the green-ish is not as pronounced. Regardless, probably wouldn't hurt to calibrate it again.
The flash worked really well -- great colors. Nice choice of shutter speed too. Nice mix of crisp shots of their heads with just enough blur on the hands to show the speed.
Notwithstanding that the EXIF recorded 1/500, I was actually shooting 1/1000. The wonderful old Nikon D1X has the CCD sensor that allows "unlimited" flash sync.