If its like most atari cabinets that were once white and installed in a smoke filled environment, then by now the white has become yellow or light brown.
This is my method, not sure what everyone else uses
1.) I First try and get it to come back utilizing a citrus based 409 cleaner / degreaser
if #1 does not touch it I go for something little more powerful that has had good results,
but you must be careful.
2.) Acetone ( Can be purchased in the paint section at walmart ), I just put some on
a clean cloth and rub area to be cleaned, works great, evaporates fast no residue., dont
want to leave it on too long though on screened on artwork or paint cause it will dissolve
paint and artwork rather easily.
I have used the above method on several cabinets with good results, worked good on a
centipede and an asteroids deluxe machine I did.