Hi, Thanks for the PM and nice rib you have there
I bought mine form east coast fibreglass:
Coloured Flowcoat/Topcoat - East Coast Fibreglass Supplies
Mine has ral 2002 on it but on their website it nows says a BS number, if I were you I would give them a call and ask to speak to the technical guy as he is really very helpful.
I bought Gelcoat, flowcoat and gelcoat filler all mixed up in ral2002 international orange.
With regards to the fading I used a fine grade of wet and dry used wet and the original colour will start to show when you sand back your repairs. Don't try and rub down the whole boat, just the area around the repair, keep the area small with a very light rubbing motion and keep adding water.
After finishing my SR4 I realised that the sea didn't care if my rib was faded or not although once you get the hang of it you can work wonders.
Here's a before and after picture on my 4.7 console after I did a repair and blended in a faded area.