The base, shadows, and highlights should all be within one color hue. It's not interesting, though...The old mainstream method was scanning and using bezier, but lately it's common to scan, clean up, and just color it like that.Galge coloring is basically all consistent, with no individuality. Each maker has their own quirks, but even if there are several graphic artists involved, all the images in the game still have to feel like they're of similar quality.Getting a consistent look from individual artists like in Littlewitch's "Shirotsumekusabanashi" must have been hard.Gal-game coloringMake the lines thicker
※Color only the lineartDon't let the colors get muddy