How to change screen background to pure black in the Phone app?

[laz232]

Since iOS 17

Phone App (default) when making a call / whilst in a call the background is a dark grey to light grey gradient.

I want it to be pure black - like my background - how it was in iOS16

How to change?

 

[Paddle1]

The only way for it to look different is if the person you are on a call with has a contact poster. They've redesigned it for the posters and if there's no poster you get the generic grey.