Quote, (The stal isnt really orange and blue it is in fact white)
This is caused by the different temperatures of the light sources, a very interesting issue!
Ever taken a snap inside a room lit by electric light, looking through a window or door to outside?
Depending on the "white balance" setting used, the inside may look natural, whilst the outside appears blue-ish, and conversely, the outside may look natural, but the inside looks very yellowish.
Had some interesting times re this issue, taking piccies in Ingleborough Cave with flash & the tungsten light in the cave, we needed yellow filters on the flashes to make the lighting all the same "temperature".
Another one was filming a Ceilidh band with Sid, multiple cameras were used, and all had to have the white balance "synced up", i.e. all cameras were set up whilst metering white balance against a piece of white card, this avoided shot transitions between cameras changing colour on screen in the edit.
Most people will probably never mess about with the white balance settings on their camera, but it is worth having a go with.
Take a look at this piccie of Gaping Gill main chamber, the lighting is by the BPC's floodlights, white balance biased toward these), see how "blue" and cold the daylight looks coming down the main shaft.
http://www.askged.com/Portfolio%20small/GGMC.jpg
Cheers & TTFN, see you all at Hidden Earth I hope?
Basher