Thom points to a handy little article on how to use color temperature to good advantage in your photography. Great stuff for mixed light photography.. some good stuff for experimenting!
When shooting mixed light situations, try setting your WB to the ‘sunny’ icon. This will lock the WB at around 5500K and accentuate both the low temperature tungsten light AND the high temperature blue natural light of dusk or pre-dawn. But experiment for the best results - every situation is different and sometimes setting your White Balance on AWB can be very effective.