I'm 200% positive that it will make a superb neck wood. I've still got 1 more neck blank which I plan to use for my brother in-law's axe once I finish these 2. BEST tap tone I've ever heard. Beats any mahogany, maple, ebony, indian rosewood or cocobolo I've had.
Just don't forget it's a good 25% heavier than the heaviest ebony, so plan ahead to avoid the imminent neckdive.
I just used bog-standard food colouring you buy from supermarkets (Tesco in my case).
As it will be water based, you'll need to make sure that whatever you use to seal it afterwards is compatable (I used Acrylic automotive lacquer from Halfords). If in doubt, test it on a scrap bit of wood first.
also remember: the lower the tuning, the lower the master volume on the power amp section. The low end of the amp (from the bass knob) distorts in the power amp section, and the lower you tune, the clearer it needs to be. Turning the bias knob towards the right gives you a cleaner less fuzzy gain, which is also better for warmer hotter and clearer tones. If you want it nastier, then turn it to the left. Turn SAG off for super-instant tones (i love doing this).
Also, try using the Q Filter effect to boost the front of your amp. Set it to HP, the frequency to somewhere between 15% and 25% (you have to try it and tweak it) and then carefully turn the mix up from 0% until it sounds better. The gain knob doesn't have to be higher than 0% unless you want more boosting.
I am still discovering awesome stuff on this unit myself!