In kwrite I can select a particular color schema for the present session. The option is grayed out in Kile, even though both are using the same katepart backend.
Sorry, but I can't reproduce the problem that you describe. Maybe you have some special set-up?
This bug has had its resolution changed, but accidentally has been left in NEEDSINFO status. I am thus closing this bug and setting the status as RESOLVED to reflect the resolution change.