|Colours||Silver with Red Accents and a Navy-Blue shoulder.|
When you read that the Ultramarines sired ~50% of all known chapters, that is no understatement. Just like many other chapters out there these guys are probably there for you to start your own narrative in 40k. Although they did help out in the Plague Wars. Oh and their homeworld sounds like the word "Periphery," make of that what you will.