Shaders don't mark any exposed properties as "Main Color"


This breaks any code that uses "someMaterial.color" without checking and forces implementation of code paths specifically for UnityGLTF materials.

Start by locating the UnityGLTF shader files and inspecting how exposed color properties are declared and identified by Unity. Reproduce the issue with a Unity material, then verify that the relevant shader properties are recognized as the material's Main Color and that material.color works without a special code path.

Written by the indexing model from the issue text.