What have you used when shooting at an outdoor stadium, when the lights are also on for supplemental lighting? When I try auto, it seems too cool, but none of the other preset values seemed to work well, either. I did some color correcting in Aperture to get a result I liked, which seemed to be right around 4000K. Can I translate this to a 'custom' WB in-camera then?
Camera is Canon 5D mark III. I don't have any of the tools like a lens-sock/cap to shoot a custom WB frame as I don't do this kind of shooting too often and until now the presets have all been satisfactory for my needs. The time of day was twilight (clear sky), moving through sunset then into darkness where the predominant source of light was the stadium lamps.
Also, are these usually mercury vapor lights? Obviously they're not high-pressure sodium as they don't have the orange tint.
Thanks to all for your help!