People made a pretty big fuss about the Pixel 2 XL’s display for several reasons, one of which was that its colors were too muted. To alleviate this issue, Google said that it would add a mode that would enable more saturated colors via an update in the coming weeks.
[Update: Pixel 2 too, mostly] Pixel 2 XL November security update adds promised saturated color mode was written by the awesome team at Android Police.