Here's the stuff: http://www.dmcolor.com/products/
You can find it at floral and craft stores. It is UV resistant, waterproof, and adheres to fabric superbly. I first ran into this stuff when I was a professional kite maker (yes, kite maker). There are still quite a few guys that decorate ripstop nylon kites with this stuff. Kite's sit out in the sun all day, get rained on, and the fabric stays soft even with the paint on them. I've got a few of my kites that have been flown for twenty years that I used this paint on.
And I also "restored" some old saddlebags of mine with it. I bought the bags used from a fellow inmate and they were sun faded just like you show. I vacuumed the dust off them and sprayed them with a couple light coats of Design Master in black. They looked great for the next two years that I owned them before I upgraded to some Wolfman bags.