Well ,it goes something like this...
When I bought the boat from Al, he'd done a great job of cleaning it up for the unsuspecting punter. OK, that's not strictly true, 'cos it was Laura who did a great job of the cleaning!

(And despite the leg-pulling I appreciate their efforts!)
Anyway, after a couple of season's use I decided that the tubes needed cleaning and used some TFR. Diluted, it didn't seem to have much effect, so I tried 50/50 and it brought the tubes back, but not brilliantly. I used undiluted TFR on some areas where there was serious discolouration and wasn't too happy with the results. Subsequent cleaning gave me the distinct impression that the tubes were getting duller with each application of TFR, and when I found a couple of photos from early trips I was shocked at how grey and faded they had become. This was confirmed when Al accompanied me on a trip round the IOW last year when he appeared shocked at the deterioration of the tubes. At this point I hadn't used any UV protector, but the boat's kept under an all-over cover and I was regularly cleaning the tubes. Over this winter, the boat has spent a lot of time with no cover and the colour deterioration is really shocking; I've been pessimistic at the likely outcome of cleaning. However, I had a "leap of faith" on Sunday - after using the last few drops of Pro Marine Ribshine in an old bottle, the results are startling. The colour restoration is fantastic, much better than TFR ever achieved, hence an order to IBS for three more bottles which have arrived today, and an order to The Polishing Company for 2 bottles of 303 protectant, due tomorrow.
I'm aware that the blue of my tubes is one of the worst colours for fading, so this is probably a fairly extreme case and many other RIBs with "kinder" colours won't suffer as badly. Yellow is generally known for being a more stable colour, this is borne out by the yellow tubed RIB stored next to mine which never has a cover on it yet doesn't look too badly faded.
PS - It's worth a look at this thread, I want to achieve a similar result to Guy but without three steps and without the hazard of unpleasant stuff like toluene!
http://rib.net/forum/showthread.php?p=205199#post205199