I recently upgrade tires from the stock BFG 32's to 305/70R17 GY MTR's with Kevlar (34's). I really wanted 35's, but that little bit of extra height would have forced a regear, and I don't really need that expense right now. The problem with the 34's though is that they only come in OWL. I prefer blackwalls.
I researched this on JKO and elsewhere and came up with a product called Miller Tire Black. Some said it worked, some said it didn't, but for $ 29 on E-Bay, it was worth a shot. So I ordered a bottle. Here's what I got.
The smallest amount you can get is a quart. I thoroughly cleaned the tires then applied it with a foam brush. It says to cut it by about 50% but I cut it by only about half that. It brushes on easily, but it will run or puddle if you get carried away. The puddles blend in after a day or two. I let the first coat dry for two days then applied a second. Then after three days of curing it got it's first bath. No issues. No white spots, no fading, the tires look like factory blackwalls.
My spare took about four weeks to show up, so I took pictures as I applied the first coat this afternoon. Here's the factory OWL.
Here's halfway through. Took maybe 30 seconds to coat one half of the letters. Note that it looks "wet." Then note the dry tire. After a few days it blends right in.
The here is a tire on the ground that was painted four weeks ago.
So far I'm pleased. I expect I'll rub some off and have to touch up from time to time, but with a quart I could paint a fleet of OWL's for years. Pretty good stuff so far.