It's definately green, ND, but you know these Klingons might make some artistic changes based on house or whatever. The original colour scheme was a pale blue-ish green, and was later recoloured to look less saturated and added some brown panels and more detail.

This is a good shot of what I'm going for :-

If you look at the studio model, you can see that it's a bit bland. Either it's faded over the years, or they did some post production enhancements :-

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