Yes, Chameleon Pens work on wood!
We would recommend using unprimed/untreated wood with the Chameleon Pens. A primer could clog the pen nibs and also react with the inks in the pen.
When you are coloring your design on wood, you may experience a light bleeding of ink. In order to stop/ minimize this, you will need to seal your outlines with a clear embossing powder (never use colored embossing powder as the pigment in it will clog the nibs) and then heat set.
We would also recommend using your bullet nib on wood as the harsh surface may damage your super-soft brush nib.
Also, like any porous surface, it will soak up more of the ink, so remember that when you create a blend with your pen, you will need to use longer fuse time.
Chameleon Pens will be permanent on wood, however, if it gets wet multiple times it is possible for the ink to slightly fade. If you wanted to use a varnish over the top to prolong this, then we would recommend using a water-based varnish and testing on a small scrap of wood before use to ensure that there is no reaction.