Exhaust Cloud when Starting Engine

[fienloco]

Mine is doing the same thing after doing a head gasket. I have been told it means your valve guides are worn, they say. Mine were checked out and I was told they were ok when the head was machined. I have also noticed the fuel smell as though its too rich same color smoke. Which could be leaking injectors a faulty coldstart injector or a fuel relay issue in the system.. Answer me this please. Do you have any lack of power?? Keep me posted if find anything out cuz Im trying to find out the same as I have a lack of power and that smoke that clears up and dont know where I should start.