I am re-texturing the Poser 5 male double-breasted jacket. The original is a crocodile texture which is, well, not very classy. So I made a brown, grey and navy version and they look fine except for this one green polygon on the lapel. tried a procedural texture, and it is still there. I removed all textures and it stays. Looking closely, it is even there using the original texture. What is going on?

Poser 11 Pro, Windows 10

Auxiliary Apps: Blender 2.79, Vue Complete 2016, Genetica 4 Pro, Gliftex 11 Pro, CorelDraw Suite X6, Comic Life 2, Project Dogwaffle Howler 8, Stitch Witch