You can copy simply copy the CRTShader.shader to any ColorRect. You can also just add the CRTScreen node to your project (a node that sets some of the shader parameters automatically). For Godot 2.x ...
An extremely lightweight Blender add-on that can apply cel-shading materials to objects. It also provides a one-button solution for applying cel-shading materials to VRoid created models (needs to be ...