Since diffuse receives light, it comes out as a gray color even when set to white (because of the ambient color, which if changed to white makes the scene far too bright), which isn’t what I want. One way could be to have something not receive light, but still receive shadows, but I can’t find anything like that. Think of it as looking vertex lit (or being vertex lit) and still receive realtime shadows. Is this possible, and where can I find this type of shader?
You might want to change ambient light to white. Go to “Edit” → “Render Settings”