Hey there! First of all, I always recommend painting on a light or neutral gray background, since it gives you better control over your values, instead of painting in a pure white or black. Regarding skin tones: the values between the shadows and the lights are very close, and both have almost the same level of saturation, that's why it looks dull. The shadows clearly need to be darker but also more saturated; speaking in terms of a “neutral” skin tone. Of course, this can vary depending on the skin color, which is why I’d recommend doing skin studies, regardless of whether your goal is to paint in an anime style. If you look at the sphere I painted, you can see that the lights remain fairly light and desaturated, while the saturation increases as you move toward the shadows. And since skin isn’t made up of just two tones, you can also introduce reddish or orange tones in the midtones (the transition between light and shadow) to achieve more dynamic and believable colors. Again, regardless of whether your goal is to paint anime, I highly recommend doing realistic studies so you can better understand how things work in real life and then translate that knowledge into your style. If we don’t understand how things work in real life, it becomes very difficult to apply them effectively in our work. Hope this helps!
