Hi all (sorry if this is in the wrong section)
I've been playing around with the idea of having applications sitting on the desktop background ready to be used when needed (such as kcalc), with their borders removed and all their colours changed to either white (text) or black (everything else), using a second kde configuration directory of course so as to not affect the other windows. (I know I could just use the calculator widget but it doesn't do hexadecimal numbers.)

It works fine, at least when its positioned over a black part of the background (such as in the middle of a mandlebrot circle, but the terminal goes there). But it would be much more configurable if it was just white text on nothing, just transparency. Then it could be positioned anywhere without blocking the background. I've installed oxygen-transparent in hope of achieving this, but unfortunately it just makes the background transparent and the buttons are still opaque. I have a small amount of experience in programming so I might be able to make them transparent but I haven't a clue how transparency is implemented in kde. Perhaps someone could point me in the right direction, would it be possible to edit the c++ files that came with oxygen-transparent to do this? There's no SVGs in there.

Or if it may be easier to edit a really simple theme such as Plastique to make the background transparent? I've grepped nearly my entire computer and can't find anything other than the .desktop file for the plastique option in "application appearance", so where would it's configuration be stored? Or perhaps I could even modify the source of Kcalc to enable transparency, after all the terminal and Conky has it, so I'm guessing it would be possible?

Thanks for any help or advice. (typing this post late at night so hopefully it makes sense)

You might also have a go at doing this using the QtCurve theme. You can set window background transparency (opacity) as well as using transparency in the gradients used by the widgets. It looks like you will still end up with a single-pixel border on the widgets, but that's probably as close as you are going to get without getting into the code.
(I thought oxygen-transparent made the buttons transparent, except for the borders. Apparently not)