One thing that always bothered me in Black Flag is the Spanish uniforms. In pre-release, they were white, which was historically correct. In the released game, they were changed to yellow with
How accurate are the soldiers' outfits and warships in Assassin's Creed IV : Black Flag? : r/AskHistorians
Nicolas Didier - Spanish Captain suit
Spanish Succession at Assassin's Creed IV: Black Flag Nexus - Mods and community