 So you're not sure which shader technique to use. Not a problem. There are two main techniques you can use to get started. You could put all your colors on a texture map or you can assign colors through materials. Now assigning colors through materials is a little easier. So that's the one I'll be showing you today. To start, you'll need to create a basic color material. So if you click here, new material, you can delete the principle, Shift A, S, Diffuse BSDF, Shift A, S, Shaded RGB, Shift A, S, Color Ramp, Drag Diffuse to Shader, Shader to Color Ramp, and Color Ramp to Material Output. Then go here and change this from linear to constant, decide what the main color is, decide what the shadow color is, move this to decide your threshold, and believe it or not, that's basically it. You can download more advanced materials from Gumroad or Artstation if you want, but honestly, this setup is generally all you need. If you check the Callisto model, which looks beautiful, you'll see she has a very similar setup on her materials for each color. Let's say you wanted to apply this color to this area here. Well, to do that, first click the object, press the plus, and select the material we just created. Then go to edit mode, select all the faces you want to have that color, hit assign, and you're done. Now one drawback to this method is you can only put the colors where the faces are available. If you look at Rookie's Callisto model, you will notice that in order to have the white separated from the pink, she literally modeled a separation line into the topology. So in this style, you'll generally have to separate colors with real topology. So just make a material for each color and then just assign them to the faces. Real simple, but if you do it right, it can look pretty good. Hope that helps, and as always, I hope you have a fantastic day, and I'll see you around.