I remember that the dark tooltips felt strange to me when I started using breeze.
Now that I am used to it, I actually prefer the dark tooltips because of their high contrast to the other GUI elements.

But as breeze dark uses dark tooltips too, this change seems reasonable and should fix the issue. (Breeze icons will never be too light, as they would be invisible on the usual GUI elements then.)

Could you give WindowBackground (239,240,241) and WindowText (35,38,39) a try? Breeze dark uses them too, and in my opinion the resulting tooltip stands out a little more.

VDG What do you think?

I think they both look fine, this is just a suggestion because the icons aren't showing up. I tested this a little further and it looks like if a change were to be made it would probably also need to be applied to the breeze gtk theme as the qt breeze colors aren't applied to the gtk counterparts. Another solutions would be to not use monochrome icons in tooltips, or to use the correct ones based on the background color.

Would you mind using standard Breeze colors and shadows when posting screenshots that depict visual changes? That makes it easier to see what's actually been changed.

I also prefer the higher contrast of dark tooltips. There shouldn't be any action/symbolic dark icons in tooltips to begin with. Fonts has a different icon for me here but that might be a high-di issue. How about we "fix" System Settings to use the Selected icon state for tooltip icons, that will use the highlighted one like in hovered menu items. That might cause issues in other configurations then but it fixes the default case.

I also personally prefer dark tooltips.

anyways this change has to be agreed upon widely in the VDG

Okay! I never made a patch before or anything so I don't necessarily know the procedure, just wanted to throw in my two cents. Thanks for taking a look!

In D11180#223070, @progwolff wrote:

I remember that the dark tooltips felt strange to me when I started using breeze.

Dark tooltips were present since good ol' KDE SC 4 times. ;-)
I think because they were dark for so long, most long-time KDE users will prefer dark tooltips.

In D11180#223647, @broulik wrote:

How about we "fix" System Settings to use the Selected icon state for tooltip icons, that will use the highlighted one like in hovered menu items.

+1. Just to clarify, the tooltip icons are still "fullcolor"(not monochrome), right?