The Community of Disc Golfers and About All Things Disc Golf
I have come across this problem when dyeing Pro PUTTERS only. I've never had an issue with drivers/midrange. I've had several Pro Birdies/Rhynos/Pigs that I couldn't get better than gray after leaving it in black extra long. I have no idea why, but I suspect a slightly different plastic formulatioin from (the ever inconsistent) Innova.