Inverted normals of fbx model?

When I import this fbx model, some parts (color palette) of the model is inverted, the front cap of the object is not visible.
I tried to do scale the geometries x so it is inverted; that would solve the problem, but the thing is: I have a lot of models which I load, some are normal but some are like the color palette; how can I know which ones do need object.children[0].geometry.scale(-1, 1, 1); and which not?

I am using the newst version of thee and fbxloader from examples/js.

painting-kit.fbx (1.3 MB)

image