I did my cloth seats & they came out great, but since my car is a daily driver, the color wears off on the drivers seat...I'm redone just that seat twice since originally doing this aout a year & a half ago
I spent $6 for 3 fine tip fabric dye pens at Hobby Lobby
I used one for the back seat & shifter boot, & one for each front seat...none ran out, but I wanted fresh tips...I did my best to stay on the stitching & keep off the cloth...I would do about 6" then blot with a dry cotton cloth (old sock)...DO NOT RUB, it can smear the dye into the cloth around the stitches...here is a pic of the back seat with half done
and here are pics of the finished product
& here is a close up shot...you can see a little bit of dye on the black, but from more than about a foot away, it's impossible to see
all told, it took me about 2 hours to do it all