I have found the following message in Userguide - under the hood: To test that the function does what we expect, double-click on the <guilabel> setColor</guilabel> entry. To set the color <varname>c</varname> , click on the color selector button, and choose a color. Set whether the color should be color A with the checkbox. Click <guilabel>OK</guilabel> and the background color is set.
I have tried to test it and there is no "setColor" entry in any of my programs in kdcop. The closest one is setPalletteBackgroundColor(QColor). BTW. kde-doc-english is not mentioned on http://www.kde.org/mailinglists/ page. Please CC me with replies, as I am not on the list. Regards Krzysztof Lichota (Polish translation team)
