Make tooltips and popups stand out more from the background

[PulsarFX]

In the default themes tooltips and popups look the same as the main window layout.
This makes it hard to see what is inside the popup / dropdown and what is in the background.

Here hides an opened popup element:

I added this CSS to make all popup elements darker to make them distinguishable.

Can we add more darkened popup elements to the default themes?

/* make all pop up elements darker, to make them more distinguishable from the main gui */
.popup,
context-menu,
menu,
menuitem > arrow,
tooltip,
popover,
popover #bauhaus-slider,
#range-current,
.dt_bauhaus_popup
{
    background-color: shade(@tooltip_bg_color, 0.5);
}

This is what the darktable theme will look like with visible popups:

[TurboGit]

The default theme is lighter on my side, and the tooltip readable... which version of dt this is?

See:

I'm not opposed to a bit more contrast, but we must at least see the same thing.

[PulsarFX]

Screenshots are from darktable theme in 4.8.1

Tooltips are visible not in all cases. Try the popup element from the first screenshot on your theme.

[TurboGit]

Still readable to me:

[TurboGit]

The change you propose has too much contrast for the gray interface (default theme):

And also for the dark theme. It is ok only for darker theme to me.