How? Nuka's colour looks more like blue when he's at the Elephant Graveyard. Scar's looks more like green and dark grey. Plus, even if the colours match, it doesn't change the fact that in the daylight their fur colours are different. Even SIMBA could get in there and get the same dark colour.

You have too look at the contributing factors though.
Scar surrounded by glowing green smoke and geysers that make his fur more of a greenish color.

While here where there's NO smoke, Scar's fur is visibly darker

I still believe the be prepared scenes where his fur has a greenish hint is still similar to when Nuka visits the EGY

Here where the lighting is similar, Nuka and Scar's colors are very similar Nuka's being darker.


Nuka's mane appears to be brown but nothing is SP is truly black.