Star Wars: Rogue One - 11 Biggest Unanswered Questions
3. Why Is Admiral Raddus A Different Colour To Admiral Ackbar?
The Question: Being a member of the Mon Calamari race and an Admiral, it's not too surprising that Admiral Raddus looks extremely similar to the much-loved Admiral Ackbar, but why is his skin coloured grey instead of the usual brown?
The Likely Answer: It's never explained in the movie, but Lucasfilm Story Group’s bible-keeper Pablo Hidalgo has confirmed that the reason for Raddus' skin colour is his residing in the "colder polar extremes", while Ackbar and those like him grew up in more tropical regions.
It's a pretty damn reasonable explanation: nothing more to it than that, and nothing to argue with here.