My 99 GT 4.6 2V smokes at idle is it's more blue than white. It smells real rich. But, at high RPM it's fine. I have noticed it using oil. It seems to stumble at 4000 RPMs but clears up around 5000. There no smoke at high RPM. Just hoping to get some ideas.
Usually: white-coolant; blue-oil; black-gas. Usually blue at idle and when taking off at first is valve seals/guides. Yours is weird with the rich smell and blue/white, so I would do a compression check wet and dry.