white background?

In all menus, no. On default watch faces that came installed on your watch, usually Yes. You can swap black to white for the background.

It's 1 year I wait for this on my Fenix 7....

Agreed. Both my F6X and Enduro were easier legible while surfing in the menu.

I guess the change of the menu background color had something to do with the general lower readability of Enduro 2 compared to its predecessors. I mean it was the only way to get back some of the loss.

Fun fact: I am testing the new functions of Enduro 2 vs Enduro. The Distress Pattern feature sounded good, but when I saw the black background and the tiny white fonts with which my emergency contact name and emergency contact phone number were displayed I started to laugh.

I hope that in an emergency situation  I would be found by an eagle-eyed guy. :-)

There is a pinned thread on the FR955 forum addressing readability, colors, fonts, visibility of UI elements:

 https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-955-series/380588/if-you-need-glasses-to-read---please-share-idea#1849682

The more people 'share the idea' with Garmin, the better:

www.garmin.com/.../