The bluish and bright white bulbs are generally considered the upgrade bulbs, and cost slightly more. If you want an upgrade in lighting, go with the a pair of the Sylvania Silverstar or equivalent to replace the headlamp bulbs. You will realize much more useful benefit from spending the money on that. The factory fog lamps are poor stand ins for brand name aftermarket driving or fog lamps that have been properly selected and installed. The design of a fog type lamp really only fills in the thirty or so feet of roadway directly in front of the car.