>>3804200Anon I didn't do much. As for me personally, it's not very relevant, I learnt the basics by printing in the darkroom. With colour, you have to set the WB and exposure yourself, by adjusting the filtration on the enlarger head. Since each "try" takes time to expose and develop until you see the result and adjust again, you become more observant about how things work.
What is relevant though is some basic colour theory. And I mean really basic. Learn the pairs of complementary colours: Green-Magenta, Red-Cyan, Blue-Yellow. There's even a silly mnemonic rule: General Motors Red Car in my Back Yard (GM, RC, BY). This goes a long way. For instance, you notice a green cast in the shadows. The complementary is magenta, so you have to add magenta in the shadows to cancel it. Many ways to do that, for instance you can go to curves, select green (or magenta) and drag the "black point" of that curve to add or reduce the said colour. In this way you affect only the shadows. Usually that's enough, but if not (say the cast extends to higher shadows), you add a point further along the curve and drag it down too.
Or you could use some of the selective colour/recolour tools, select the region you want (I mean shadows, or midtones, or highlights) and add or subtract hues to specific colours. In our case you'd select shadows, then green and add magenta to the green.
Then you do similarly for the highlights - if there's a cast there - and you're golden for most cases.
Sometimes casts are a bit more complex, consisting of mixtures of primary colours, not just one. Say an orange cast (red+yellow). If you identify one component of the cast, you're good. Say you identify the yellow. You go and add yellow through curves (or any other method) until there's no yellow in the cast, so you'll get a red cast. Initially it'll look worse, but now you have a "pure" red cast, that in the next step you'll add some cyan to neutralise.
This gets you 90% there in the vast majority of cases.
