The Rainbow Warriors were a Loyalist Space Marine Chapter known to be a Successor Chapter of the Ultramarines, raised during an unknown Founding. There is almost no further mention of this obscure Chapter in official Imperial records. The Chapter's homeworld is called Prism. This Chapter's current status is unknown.
- The Blood Star Campaign (748.M41) - A massive daemonic incursion into the Scarus Sector is heralded by the star Ares turning an ominous blood red. The Rainbow Warriors, Relictors, and Fire Lords eventually halt the invasion but take grievous casualties, including the loss of all three Chapter Masters. The Imperium grieves for three of its mightiest heroes.
The homeworld of the Rainbow Warriors is a planet called Prism. Almost nothing is known about it in official Imperial records. It should be noted that in the official records of Space Marine Chapter Homeworlds, there is a map displaying the galactic locations of the various Astartes Homeworlds. But in the case of the Rainbow Warriors Chapter, instead of displaying their planet with the Chapter's name, it simply says "record deleted" where their homeworld should be. By looking closely, it is clear that the Chapter badge of this deleted Chapter is that of the Rainbow Warriors.
The Rainbow Warriors wear blue Power Armour with a multi-coloured rainbow stripe through the centre of their helmets. The Aquila or Imperialis on the chest armour is yellow. The white squad specialty symbol -- (Tactical, Assault, Devastator, or Veteran) -- is indicated on the right shoulder guard.
The Rainbow Warriors' Chapter badge is a white winged lightning bolt.
A Rainbow Warriors Chapter badge is present in the Command Center space on the board of Milton Bradley's board game Space Crusade. It is possible the Chapter was named after the Greenpeace ship, "Rainbow Warrior", sunk in 1985 by operatives of the French intelligence service.
- Codex: Space Marines (6th Edition), pp. 64, 67
- Codex: Space Marines (5th Edition), pg. 30
- Warhammer 40,000: Rogue Trader (1st Edition), pg. 169
- Mission: Purge (Audio Drama) by Gav Thorpe