That's pretty normal for a 2-stroke to smoke more when cold. IMO, the oil just doesn't get burned as well until the engine warms up as combustion temps will be down, plus the oil that was on the surfaces in the crankcase when it was shut off tends to puddle, then gets run through the combustion chamber not well atomized, so it doesn't burn very well in that state. Every 2-stroke I've ever had, had that trait.