Tires’ turning brown is called “blooming� which is a recurring process and factor of rubber and has zip to do with your dressings. Certain plastic trim also “blooms� and is recurring which causes black trim to turn grey. Both rubber and plastic are made with petroleum by-products which creates this process.
Wesley’s is great on whitewalls and raised white lettering however DO not get this on your calipers as this product will tarnish them and if they are painted it will dull the color in a heartbeat. :shocked Read the labels. :bigups
I use Meg’s APC+ cut 4:1 on black walls and it works just great.
I do hope this helps on the mystery of browning on your tires. Al