Changing plasma theme

[Jeremy Sanders]

Kevin Kofler wrote:

> It's a feature of the new Oxygen theme to be black. The "preview" only
> shows some basics of the color scheme, it's not a real preview.

I find it a bit odd that the main colour of plasma on my screen is now blue-
green when it was black under KDE 4.1. I have no idea whether that's Oxygen 
or some other setting. The preview should show the main colour at least.

Thanks

Jeremy