Materials on model don't show up in build

I’m trying to assign a material on a model with a simple color shader (meant to show that the character is “empty” as it were) and have it be “filled in” with one that uses a standard shader and the diffuse and normal maps associated with that model when a certain button is pressed. It works fine in the editor, but when I build the project and play the scene it instead switches to the default material (the blank white material that uses a standard shader). For whatever reason, though, if I give the simple color material a standard shader everything works as it’s suppose to.

Incidentally I tried adding the unlit color shader to Edit > Project Settings > Graphics > Always Included Shaders and it’s still doing this.

The standard shader has many different variants, which are only compiled when needed. This includes variations for the assigned texture maps. If your build doesn’t include the compiled version of the required variant, it won’t display. (While it will always display in the editor.)

To solve this, create a material with the intended textures assigned and link it from a script (or model) in the scene.

It’s only when I try to link the material through the script that this problem occurs, though. The materials display just fine if I just drop the model in the scene fully filled in.