What colour should the supply pipes be inside the building be for a commercial sprinkler system?

Specifically a large retail warehouse enviroment uk based. is there any legilsation which covers this topic and if so where can i access it. thanks
Answer
Red for sprinklers yellow for gas blue for fresh water brown waste water electrical cabling is usually black but this is not always the case in every factory but red is the sprinkler systen note this is for the uk