Fatorytalkview ver 12 display background color

[nmk34]

Hello
i can not change one of the displays background color, the "Apply" button is greyed out. the firmware 5.10(older PV PLUS1000). I can change other displays background colors but not this one. I can select the color in the properties, but
I can not apply it to the display. why?
Thanks

 

[Operaghost]

Version 5.1 doesn't support gradients. Maybe that is the reason.

OG

 

[jkerekes]

Is it possibly wallpaper instead of the actual screen background?