UniUnlit

Probably UnLighting for short Unlit

Unlit

It is saved as a glTF KHR_materials_unlit extension.

Shaders that can be exported as Unlit in Unity

Function	color	texture	vertex_color	alpha/cutout	no culling
glTF	✅	✅	✅	✅	✅
UniGLTF/UniUnlit	✅	✅	✅	✅	✅
Unlit/Color	✅
Unlit/Texture		✅
Unlit/Transparent		✅		blend
Unlit/Transparent Cutout		✅		cutout

vertex color

Only UniGLTF / UniUnlit supports vertex colors.

• Mesh contains vertex colors

• Material is a Unlit

In some cases, importing will apply the vertex color.If you apply Unity’s unlit system material to a model that does not require vertex color and export it,The next time you import, the colors may change unintentionally.In this case, you can export Mesh without vertex colors by enabling RemoveVertexColor at the time of export.