From a camera review:
The camera app offers AI scene recognition - you'll see a small icon when a scene is successfully recognized, and the software will tweak all settings accordingly. Food, snow, pets, sunsets, grass, among other scenes, are detected mostly correctly.
So this is possibly a case where the "mostly" in "mostly correctly' applies. The scene isn't recognized properly and the camera applies the wrong tweaks (for instance adding some red for better skin tones). What is the scene icon? Can you disable this (or use a different camera app)?