Thanks for the feedback guys...The point about the heat retention properties of black hypalon is a good one!
I don't really have anything against orange (which, afterall, would just be replacing like for like): However, I had thought that the black ribs I'd seen looked smart and that black might be more dirt / fade resistant? Is this the case, or does it show dirt and fade in UV just like other colours?
I suspect that the answer, as for all tubes, is regular use of cleaning and protection products, preferably allied to the use of a cover, but any more info. on this subject would be gratefully received! (new tubes are a big investment