Played around with OpenSCAD.
Was inspired by openCscad from Thingiverse user smcameron:
http://smcameron.github.io/opencscad/

Tried to do the same thing with recursion within OpenSCAD.

For a more natural looking tree, please look at this thing:
http://www.thingiverse.com/thing:128686

UPDATE:
As Thingiverse User Ablapo pointed out, recursion is not (yet?) supported by the Customizer. So i changed the script to a 'pseudo recursive procedure': I just chained the needed the modules together!
Not unbeautiful, but it works this way.
I will post another truly recursive script when the Customizer can handle it.

UPDATE II: I did some optimisation in the code, it runs now twice as fast... and with more colors!