Ubisoft has released official cosplay guides to assist the ever-growing Rainbow Six Siege cosplay community, worldwide.
At present, not all Operators have a cosplay guide. However, I believe more are being worked on.
Each guide has detailed shots of the Operator, including hex colour codes for their uniforms and other details. These are invaluable resources to any cosplayer wanting to start a Siege cosplay!
Here you can find the released guides: