I do alot of night driving and the local auto shop recommended some stuff to clean up the yellowish film of the lights. They also recommended changing to the silverstar lights. I know the high/low beam number is 9007, but i'm not sure about the fog lights number.
Thankyou for your time.

'97 expedition

 

I just used some Meguires Mag and Alumnium polish on a 95 thunderbirds lights. It removed most of the yellow on the headlights.

The fog lights for a 97 are 9006ST

http://www.sylvania.com/bin/carApp/c...tion&x=19&y=13

 

I put silverstars in my 99 camry--big difference-- on my 97 Expy I used meguairs and simichrome polish which worked very well--do a search on headlight lamp cleaning --you will be amazed at the hits you get

 

Much thanks to those who answered my question, I used a chrome polish and it did remove some of the yellow, but i plan to pass it over again with a car polish and a nice buffer.