How to change Fullscreen background color?

[FKCapitalism]

When double click image file in explorer i get this screen with arrows on bottom, how do i change background color to black i cannot find this option inside Tools > Settings

1.png (269.55 KiB) Viewed 610 times

[cday]

Tools > Settings... > Browser -- Browser tab -- Preview background color ?

[FKCapitalism]

Thanks, found it
Tools > Settings > View Fullscreen "Background Color"

They call this mode "full screen", thought it was called "quick view"