Adapt to API changes introduced by b62e8888cd39301e00ad98dfe791fa66676408fb.
It adds DecoratedClient::color(group, role) for getting colors that are
not included in QPalette. Breeze used to read these colors from
kdeglobals, breaking per window color schemes. KWin now handles reading
these colors along with QPalette loading with DecorationPalette.
REVIEW: 122883
