The set of colors I use for basic overlay use to give your art a bit of spice! These are the colors I use for when I don’t have a particular color source.
I use the oranges and purples as the base color, typically the purples are closer toward the bottom or wherever the shading will go, meanwhile the blue goes over the shading and the darkest areas, and yellow are for highlights and anywhere where a light source should hit. You should blend them in but you don’t have too. I typically use the layer option overlay between 10% to 35%.