Nice shot, good colors, almost looks like a set-up photograph in terms of lighting. You must have had the camera on a tripod? If I had to guess, exposure around 1/4 second?
Yes it was on a tripod. Exposure time was more like 15 seconds. People just weren't moving around that much so they look pretty solid. I'm very impressed with the quality of color you get from Portra 160nc (now just Portra 160) when shooting night-time exposures. It handles mixed lighting incredibly well.