Re: Dark gray/charcoal colored smoke on boost
black puffs are just unburnt fuel, it's when you're running a rich. I fit's only doing them at WOT i wouldn't be too worried if it's doing it everywhere i'd look into a return
If your puffing black smoke with little to no boost a leaky injector could be an issue. Definitely fuelling related. Do you have an intake leak? That could make the ECU it's sucking in more air than it thinks and trying to fuel for it.
Black - unburnt fuel
Blue - Bad. Coolant
White - Condensation