You don't sound thick, at all, to me.Originally Posted by Blighty
There are a number of factors affecting color balance: the color temperature of the lighting is one, and probably the most significant. There will be variations due to processing - the age of the chemicals, the composition of the water used to mix them,... I couldn't begin to list them all ... I think the phase of the moon, whether Saturn was in Aquarius ... might have something to do with it all.
Frame-to-frame variations are less severe, however, even the positioning of the model in a mixed lighting situation can result in a different color balance, for example.
Normally, in the first frame I take, I'll have the model hold a gray card; from that I'll get a usable reference for analysis. From there, It all depends on the eye and taste, and perfectionism of the photographer - in this regard, it is no different than working in black and white.