@KUR0MlSS To be more specific: the layer with the grays is the layer which has the base color and the shadows and some lights, then there's the line layer, and on top of that is the flat color layer set to Overlay
@KUR0MlSS Yes! Actually, it's even on top of the line art layer. I think the Overlay mode is widely used for colorizing grayscale and also for color correction!