>>718199906
See
>>718198287
Now look carefully at the texture of the brown parts and the texture on the yellow parts. The brown parts are smooth like skin and lack the fur texture of the yellow. She has brown skin and Sonic has tan skin. In the Sonic generation artbook shadow muzzle is labeled as skin.

You might be right if we only had 2D to go off but there’s official 3D models with textures applied on top of the little details like Sonic’s model.