>>298807169
>>298807582
Never use black/grey as a shadow color unless the object is actually black or grey. It looks awkward on anime, and looks worse the sharper the shadows are. Shadow color should be chosen according to the color of what is being shaded. For example, look at this image of Eris. Instead of ever using black shadows, blue is chosen as a shadow color for white, and most other shadow colors are the original color with the brightness/value lowered.
Separate your materials in accordance to what the color of the objects you are shading and make different colored ramps for each one, or use a shader with shade maps for each shade position (like UTS2 or ACLS) for finer control of shadow color. If you are a PBR whore, then consider ACLS.