I had a set mounted up back in May...no idea if the letters will turn brown but so far, they look fine.

Now you have me wondering!

Have you considered different tires? Yes the options for our tire sizes are minimal but there is the Mickey Thompson Sportsman SR.

I don't think either tire is particularly good (by 2017 standards) but some say the MTs are slightly stickier than the BFG T/As and this may help avoid the BFG letter problem.

https://www.summitracing.com/parts/mtt-6...ASABEgK5y_D_BwE