How to remove color from mesh?

[Ty294]

Hey all, I have a bit of an issue going on with the Rhen Var ice cave meshes, which I am just giving a minor retexture for my map. Problem is, despite me removing the greenish color from the .tgas, there are still blotches of it within the meshes in-game:



Whatever is causing it, it results in a non-uniform appearance to the cave walls, which just makes the whole thing look bad. I'm wondering if anyone knows what causes this and if it is possible to hex-edit it out of the mesh somehow?

Thanks.