The Zion Dark theme button highlight is faulty - it highlights to white instead of a dark color, resulting in low contast when a button is clicked / hovered. The bug is not straightforward to reproduce because button highlights setting carries over from the previous theme for some time. Reproducible: Sometimes Steps to Reproduce: 1. Change theme to Zion Dark 2. Relogin (or at least restart application) 3. Click some buttons (e.g. system settings->Colors->back to Overview) Actual Results: Buttons become white on click. Expected Results: Buttons highlight to some color matching theme on click. Fedora 22
Could you post a screenshot ?
I cannot reproduce the issue in Oxygen, but definitly with Breeze. This is because the mouse-over color is basically the same as the foreground color. It is even brighter than the focus color. I'm afraid it is an issue with the color scheme however, rather than with the style itself. For instance, it would seem more natural to me to have a mouse-over color close to the selection color, but lighter, and the same for the focus color.
Created attachment 94536 [details] Screenshot of button highlight
I can confirm that this is currently still an issue with (many? all?) dark themes. @Hugo: 1. if this bug should be put elsewhere, can you reassign product/component/assignee? 2. Can you provide a workaround? (Based on your earlier comment, I feel there might be one.)
Created attachment 117620 [details] White-on-white while not hovering with mouse BTW, this does also happen when the button is just focused (active?), so this is not just about mouse-over. (Added attachment showing this.)
Possibly related: Bug 354627
This was fixed a while back. Any remaining issues would be an instance of Bug 354627, or similar.