I have noticed that on some qt apps (not any from kde, but others such as qt designer and unetbootin) the widgit theme is not KDE's standard blue, but a deep purple. This is especially evident in the progress bars. I would like to know what causes this odd change in theme and how to fix it. Thanks for any info!

Try removing ~/.config/Trolltech.conf outside of a KDE session, then changing your colour scheme ( and change it back if you wish )