There are three colors of smoke, black, blue, and white. Black is from incomplete combustion, white is from raw/unburned fuel, and blue is caused by burning oil. The most usual cause is from valve stem seals leaking. This can be caused by old/hardened valve stem seals, or worn valve guides causing too much play in the valve stem, to the point that the seal can't do it's job. Too it can come from oil getting sucked past the piston rings due to the cylinder walls/rings being glazed, etc.
In your case I don't think blue smoke is going to hurt a thing. In fact if you had a cylinder missing for awhile, if you run it long enough with all cylinders firing again, the smoke might go away on it's own. Good luck.