You could import the mesh into another blender file and check if it’s also green there.
If not, maybe check if the right texture is applied in Roblox studio.
If yes, maybe check the texture/materials in blender…maybe you changed some colors to green in an incident?
When I import the mesh into a new blender file however, it’s suddenly gray, like supposed to be.
I heard that Roblox messes up the .FBX files, so I tried to do use both .FBX and .OBJ, but none of them seem to help.
Even when I make a new place on Studio, the outcome is still the same. So it possibly has to do something with the export settings, that Roblox for some reason messes up.