Some art styles increase the saturation in their shading, I'm trying to achieve this effect as seen in cell #2 of my example image. Right now it looks like cell #3, which lacks this and looks dull in the render.
I just have #1 as a default frame of reference, and #4 is an exaggeration of the effect I want; using color for darker areas instead of just darkening. If I could achieve the effect in cell #4, I could easily change it to be like cell #2.
So far I have tried creating 2 material nodes with one of them inverted, and then mixing them. This doesn't show in render mode, and it still doesn't let me change the color where needed. I'm not sure how to go about creating the effect shown in cell #2, because I'm quite new to nodes.