We use a Qt stylesheet to style the buttons (and other aspects of the GUI theme). A report on the mailing list indicates this is not working for PyQt v5.13.0 on launch, but starts working once a tab is restarted. The report also said that it worked correctly on PyQt 5.14, but this version is incompatible with pyqtgraph (used in runviewer and IMAQdxCamera in labscript_devices), see labscript-suite/runviewer#26.
I have not tested to see if it works on PyQt 5.9.2 correctly or not (the latest version available through standard conda channels)
We use a Qt stylesheet to style the buttons (and other aspects of the GUI theme). A report on the mailing list indicates this is not working for PyQt v5.13.0 on launch, but starts working once a tab is restarted. The report also said that it worked correctly on PyQt 5.14, but this version is incompatible with pyqtgraph (used in runviewer and IMAQdxCamera in labscript_devices), see labscript-suite/runviewer#26.
I have not tested to see if it works on PyQt 5.9.2 correctly or not (the latest version available through standard conda channels)