Thanks all; it sounds like it's basically as I expected and no way to completely and accurately fix colour issues post-exposure. Not the end of the earth. Tungsten light is such an extreme example (~3 stops less blue light, the blue-sensitive layer will be completely blank/unexposed and therefore absolutely uncorrectable) so I probably shouldn't have led off with that. What is probably more useful to me is the subtle daylight/shade/flash colour-temp corrections. While I know I can get an 81B/C, it'd be nice not to have to bother.

(I got a PM saying I should use a colour-print viewing kit. I actually have the Kodak version of that and plan on using it when I start printing, I was just wondering if the process could correct for illumination rather than just film/paper/enlarger combination).

I'll have to go have a read of Ctein now as I'm lacking a good colour reference.