White smoke from a cold engine can mean one of three things. If it smells like oil, you may have wear on the valve stem seals. This allows a small amount of oil to seep past the seals and into the cylinder, which then burns on engine start up. It usually only lasts a short period of time.
Another source of white smoke is that which smells like diesel and is indicative of incompletely burned fuel due to a cold engine. It clears up as soon as the engine warms up. Sometimes it may also be caused by lower compression due to some other problem such as incorrectly installed glow plug(s) or compression loss due to cylinder or piston ring wear, or valve sealing problems. I have experienced glow plug installation problems, and that one cleared up in a few minutes after the plug warmed up and lengthened enough due to the heat to seal itself against the seat. Compression losses due to ring or cylinder wear or valve problems might not seal at all - I don't have experience with these troubles.
White smoke that smells like coolant may indicate a head gasket problem. You may have this problem accompanied by oil in the coolant, and certainly exhaust gasses in the coolant. While a coolant cloud would dissipate more quickly than oil or unburned fuel, if it were due to a head gasket failure it probably wouldn't stop as the engine warmed up.
Massive over injection due to a nozzle or injector failure will result in possibly white smoke at first, but as the engine warms a bit, you should see black smoke when the fuel tries to burn, is not held back by cold temperatures, but forms soot because of a lack of sufficient air for the fuel getting injected.
That's my story, and I'm sticking to it.
Cheers,
PH