Car starts with white smoke and ends with darker smoke?

[PimpsMcGee]

The car is a 1985 nissan 300zx with a 3.0L 6 cylinder and smokes at first white but as it runs it begins to deepen in color. Here is the address: http://www.southpointechevrolet.com/details/Used+1985+Nissan+300ZX++JN1HZ14S5FX096821+Tulsa