You don’t want your ui to be 1980s beige, but like if the plastic has been sitting in a smokers house? Weird.
But yeah, this is material you. Its a feature that makes apps match the colors of your wallpaper, and if you go to “wallpaper and style” in the settings app (at least on my pixel 3, its possible it’d be somewhere else on a phone from a different manufacturer, or potentially even newer phones from google) you can pick other color options