Weird inverse colours when rendering out Matinee

Hey guys and gals,

When I try to render out a Matinee sequence sometimes the image turns a weird inverse kind of colour, especially in the shadows.

To illustrate, this is what it should look like (older movie):

And this is what I get currently:

I can’t find anything about this or anyone having the same issue, maybe it’s a setting I’ve missed or something, but I’m at a loss right now.

Any ideas?

PS: I’m using colour grading and I suspect it to be something related to that…