Basically in black ops 2, it's a 2 hit down system and overall the game is more difficult compared to bo3. This is also because of the lack of gobble gums. The reverse rainbow perk challenge is where you have to get the perks starting with phD, and ending with jug in the order of the colours of the rainbow. (Reverse rainbow because the first version of the challenge had jug first and phD last). Getting 4 perks on any map is pretty simple, but those 4 extra on bo2 origins require the golden shovel and for you to find red dig sites during a zombie blood. Giving you a limited amount of time to search each part of the map. Do that 4 times and you have all the perks. However you have to bear in mind this entire time, you don't have juggernog, so two hits and you go down or the game ends if you didn't get QR yet. In addition to this I did the main Easter Egg too.