I rendered a red box under green light and the result is a black box. Is this how I would have to paint red object under green light? It looks really weird so thats why im asking.

Also PLEASE does anyone have any tutorials on color theory, how to pick colors in shadow and light etc? I only see Gurney's book posted here and im too beg for it. Marco Bucci's video are too theoretical, I need real a walkthrough for a painting with human figures, i tried but failed at applying his colored spheres tutorials to painting people. It can be anything, including paid courses. Theres so many resources on construction here but nothing about actual painting and colors, im feeling rly hopeless here.