Created attachment 109667 [details] demonstration. When using Breeze-Dark on Discover, the window title text color does not change. It stays black, making that text unreadable. This may be a kirigami issue, as similar things occur in systemsettings.
Created attachment 109668 [details] Nope In Discover we are using Kirigami.Heading so it's certainly a Kirigami thing. That said, I cannot reproduce when using Breeze Dark.
Are you using standard Breeze dark, or with a modified color scheme? Also, what version of Kirigami do you have?
Using kf5-kirigami2 5.41.0~1.fc27 from the Fedora release repositories. Normal Breeze-Dark. I might report this against Kirigami.
*** Bug 388461 has been marked as a duplicate of this bug. ***
it sounds to me this is probably not using qqc2-desktop-style for qqc2? how do the scrollbars look when they come up?
Moved to the git master branch on OpenSUSE and everything works fine now