Without a generated dialogs/background.svg the Background Contrast effect is used

[Zren]

Since breeze-alphablack inherits the default (Breeze) desktoptheme, it should be using it's dialogs/background.svg. The popup corners look correctly rounded so it's definitely inherited correctly. The problem seems to be that when we inherit the background.svg, it's using the light theme's contrast metadata.

When we generate a dialogs/background.svg using the AlphaBlackControl widget, it looks correct.

After finding out it's the desktop effect, I dived into all the contast metadata, and found that Breeze add this to the metadata.desktop:

[ContrastEffect]
enabled=true
contrast=0.2
#intensity is disabled, in order to auto adjust to the chosen theme color
#intensity=2.0
saturation=1.7

• https://github.com/KDE/plasma-framework/blob/master/src/desktoptheme/breeze/metadata.desktop.cmake#L102
• https://github.com/KDE/plasma-framework/blob/master/src/desktoptheme/breeze-light/metadata.desktop.cmake#L101
• https://github.com/KDE/plasma-framework/blob/master/src/desktoptheme/breeze-dark/metadata.desktop.cmake#L101

[Zren]

Changing to enabled=false does not fix things. It still inherits the enabled=true from Breeze I think.

Using breeze-dark's contrast values is better, but isn't exactly the same color as shipping our own background.svg. The panel is also a different color.