Custom Button Eyes Creation

How are the eye textures applied to the DCL Male and Female base meshes? Are they applied with some special material? I assume the texture is applied to the “F_Mask_Eyes” mesh. The problem with the “AvatarMaskEyes_MAT” material for that mesh is it’s solid black for the sample models. The eyes texture in the GLB version is simple named “image 2” and it doesn’t have a gradient so it doesn’t reflect the eye color changes.
image 2 eyes

Whenever I want to look at the eyes texture in the Materials Preview or the Render Preview, I get this strange black material on the “F_Mask_Eyes” mesh. The rest of the model has a bright purple color. Whenever I try to render out the scene, the entire model is a dark black with triangle artifacts all over the place.

Here’s a screenshot from one of my viewports so you can get a general idea.

Here’s a screenshot from my Shader Editor:
shader view

Any help is appreciated. For now I’m going to try to add the new eyes texture and see what happens.

The texture on the F_Mask_Eyes mesh did not end up working. I was able to upload just the texture. By moving the buttons around a bit I got a decent result:

Even though I created it as a grayscale image, it is not responding to any change in eye color in the Builder menu. Under properties the details for this item shows 100 triangles. However in Blender, the F_Mask_Eyes mesh shows up as 122 triangles. This makes me wonder what the texture is applied to and how.

I tried adding a new item using an eyes thumbnail I got from the Github assets directory. The location of the eyes in the 256 x 256 texture file causes them to not show up on the avatar in the builder.
No eyes eyes thumbnail

After repositioning them and adding them as a new item, they still don’t reflect the change of eye color. There is for sure something I am missing.
eye thumbnail 02
blue eyes thumbnail 02