Unlike KColorDialog, KColorCombo does not setting enable transparency even if user wants it. Reproducible: Always Steps to Reproduce: I propose to add KColorCombo::setAlphaChannelEnabled(bool) modeled after KColorDialog::setAlphaChannelEnabled(bool). alphaChannelEnabled [bool] property is also welcome. Looking at the code of KColorCombo I see there's KColorDialog::getColor() used which does not support transparency data. I propose to add KColorDialog::getColorWithAlphaChannel() by the way and use it in KColorCombo.