Nice one...but you missed a few spots

I can still see some of the spots with green.
Mic, if you want to create a similar effect use the following:
1. Copy the image and create a new image
2. Flatten the second image and use the lab colour b&w conversion Matt.K posted a while ago
3. Copy the b&w version and paste it into the coloured image
4. Put the layer with the b&w image as the bottom layer and select the coloured pic layer
5. Use the eraser - on brush setting/~10% flow (these are my preferences) - (and your wacom) and erase the irrelevant colours.
Alternatively what you could do is just duplicate the coloured layer at the start and just desaturate the layer until it's b&w then follow steps 4 and 5, but I've noticed that this is an extremely dodgy way of doing it.
Cheers,
W