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That discoloration is not unusual but normally happens over time. How "new" are the tires. Have you contacted the manufacturer?
The chemistry of the whitewall as well as the base tire and how the whitewall was applied are all factors in the discoloration. Exposure to sunlight as well as ozone (produced when electric motors start) can also create discoloration.
Many years ago Coker Tire would offer a "Whitewall Guarantee" at extra cost. It is no longer available. Their extra cost extended tire warranty includes pro-rated replacement for whitewall damage but not discoloration.
I got the tires from Jeg's, they were listed as Coker BFGoodrich Silvertown Whitewall Bias Ply Tire 550-18. They have only been on the car a couple months and never on the road, just in the shop. Three of the four tires have turned brown???
I have some stuff called "LA's Totally Awsome" that should take the Brown color out. Spray it on, wash it off. Works great on my White sidewalls that yellow.
Another great product to get them back to white is "Black Magic 800002222 Bleche-Wite Tire Cleaner". You can find it on Amazon and lots of other places. Works like a champ.
A few, maybe 5-6 years ago a friend had new tires from Coker that all the whitewalls had brown tinge to them. He actually wet sanded them to remove the discoloration. That was after using several products that normally worked but had no effect on his tires. Unfortunately he passed away shortly afterwards and I have no idea how they held up afterwards.
Bleached White and scrubbing with a Scotch-Brite pad helped keep the whitewalls on my ‘37 fairly white for quite a few years. That is quite a bit of discoloration on yours so the results might not be what you would like.
I would contact Coker for their response. A big factor is how old the tires were before JEGS sold them to you.
