Some personal notes about my own approaches to coloring/shading/lighting
My shading process isn't too special, it's just classic multiply shading lol. For lighting, I use the airbrush to go over the lit areas and set the layer to overlay (top drawing). For more dramatic lighting, I'll draw in the lighting and set the layer to screen, and also airbrush it a bit to give it some "glow" (bottom drawing).
To color my lineart, I just set my lines layer to multiply and recolor them whatever color looks good for the lighting situation I want lol
anyways, I'm just going to link these nice notes about light/color from one of my old art inspirations because they're more qualified to talk about light and color than me lol