the palette files installed by kde can be either system-wide or the user ones. the latter are in you private kde configuration folders, and they are named "oxygen colors", "custom colors", "recent colors", "web colors", "royal colors" and "40 colors" (this last palette belong to qt). in kcoloredit, you may open all of these palettes, as well as palettes in arbitrary text files, for instance *.gpl (gimp palette files).