Created attachment 128061 [details] gtk-demo toolbar vs LO toolbar. Notice the pressed button in LO toolbar and the one in gtk3-demo. The one in gtk3-demo has darker coloring for the pressed button area.
I think this was working and went awry with the fix for bug #100251
Caolán McNamara committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/core/commit/?id=7f6f5519079e3508ac1302aa5907cfc6098c525e Resolves: tdf#103320 pressed buttons appear as hover buttons in toolbar It will be available in 5.3.0. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
both now seem to work, probably need to rework the toolbar stuff to use the new css code rather than grabbing the styles of real widgets.