Some iPhone 11 and iPhone 12 users are reporting issues with the color fading on their devices. At this stage, Apple is reportedly not treating the issue as a fault, but the result of normal wear and tear.
https://www.notebookcheck.net/Some-iPhone-11-and-12-owners-complaining-of-color-fading-issues-other-red-iPhone-models-could-be-among-those-affected.527920.0.html