It's a little off topic, but is there a reason why most equipment is black and makes us look like seals? Other than that black tends to be a natural colour for rubber products.
I have a green tank light (even in daytime) which makes me easily identifiable.
Partly because it allows faster production when you dont constantly have to change colors for the same stock. They did back in the 90s experiment with diffrent vibrant colors of wet suits which appeared to at least been successful for a short period of time but for what ever reason the elder divers who were active in that time period seem to have a hay day and poke fun at those types of gear now.
Also in a non official response and more from my own point of view it does tend to make color coding for other gear a tad easier. In my case all of my emergency gear is yellow. All of my primary gear I would use is blue such as primary hose and computer hose. All other hoses I do in black.
As to an official answer sorry I cant provide one for you but I am sure someone will come along who can.