So, I've always sort of dug the Ultramarines. I play Dark Eldar, but doesn't every player have to own a small marine army (That's in the rules somewhere right? :-p ). Anyways I've also always sort of disliked the electric blue uniforms of the Ultramarines, and wanted to find a fluff reason for making their uniforms red.

So looking through several items of fluff I discovered that one of the Ultramar planets, Konor, is an Adeptus Mechanicus world. So I thought to myself, maybe these guys would paint their uniforms deep red in honour of the Adeptus Mechanicus being a primary feature on their planet.

After telling my buddy this, he pointed out that the Adeptus Mechanicus has its own body of troops to fight for them, and though the Tech Priest DO train on Mars they are a specialized troop. Which is indeed a valid point.

My question is this: How do I justify painting Ultramarines red? And would it be reasonable that a Ultramarine unit on Konor (A Research World) would paint their uniforms red.

What do you guys think?