I've had this peculiar issue with my front-left brake where I've seen a ring of rust due to non-contact. I went to a shop, was told that the pads are essentially new and probably aren't bedded yet.
Well, that was about a month and a half ago. I haven't seen any improvement whatsoever, and the brake seems to be slightly discolored compared to my others. Wheel cleaner that I sprayed onto it about 4 weeks ago still has not come off. Could I have a seized caliper? I stopped using the wheel cleaner once I saw zero improvement.
Front-left:
Front-right (what's up with the gouge in the rotor?):
Rear-right: