I want to dye the main body of a new Gossamer Gear Gorilla pack dark green. It's gray and 210 denier, urethane-coated, double wall ripstop nylon. There are other fabrics like silnylon on the pack, but I'm ignoring them and assuming they won't dye.
I'm planning to use Rit liquid dye. Will this work? Any gotchas or tips? Do I need to wash the pack a few times to remove any DWR coating?