D24060: Make KColorScheme compatible with QVariant

[Volker Krause]

vkrause added a task: T8837: QColor support for Grantlee.

REPOSITORY
  R265 KConfigWidgets

REVISION DETAIL
  https://phabricator.kde.org/D24060

To: vkrause, dfaure
Cc: dfaure, kde-frameworks-devel, LeGast00n, GB_2, michaelh, ngraham, bruns