Without this patch, changing the application color scheme from system
settings only affects some widgets. Notably, checkboxes highlighting
colors stays the old color, leading to a hodge-podge color scheme and
bad contrast on some items.
The breeze QStyle caches the colors read via KSharedConfig, so it needs
to re-read the configuration when the application color changes. Breeze
has a dbus listener on the signal we emit in this patch and will act
accordingly. Currently, no one sends this signal.
Another way to achieve this is to installl an eventfilter on qApp in the
breeze style, see https://phabricator.kde.org/D21646
This fixes the coloring of various widgets in breeze right after color
changes.
Patch will probably need manual forward-porting to master since the KCM
has been rewritten using QtQuick. I can do that, but someone would need
to test.
BUG:408416
FIXED-IN: 5.15.6
Those I haven't tested, but look quite suspicious (so please re-test):
CCBUG:382505
CCBUG:355295