Configurable Key Colour for Overlay

[Aliby]

Can a setting be added so that the key colour used for overlay is configurable.

The near black (RGB 001) is OK, but doesn't lend itself to other standard film options like a Green Screen.
An example would be to be able to use VLC to show a live play on green screen, with a overlaid backdrop image/video

[VLC_help]

I could try this at weekend. Bump this thread on Saturday if I for some reason forget this.
EDIT:
I haven't forgot this.

[VLC_help]

I made one that supports change with DirectX video output module. Because it is based on nightly build, it has some issues, for example every filter is shown twice on settings -> preferences.
http://www.megaupload.com/?d=9G8M0PH4