Unlock Diamond Camouflage for every weapon in its category.
Royalty Camouflage is a camouflage that is appearing in Call of Duty: Advanced Warfare. It is unlocked for every weapon in its category after all the base weapons in that category have Diamond Camouflage unlocked. DLC and update weapons will also have the Royalty Camouflage available once it is unlocked, though it is not necessary to unlock Diamond Camouflage on them first.
As of the February 4th, 2015 patch on PC, the camouflage was slightly changed. Instead of only featuring red gems, black gems were added as well as the overall pattern being changed to connect the gems. Console versions retain the original version of the camouflage.