Well correct me if I am wrong, I am just trying to say. and if I use the word fog light shoot me!
headlights throw a beam they fill up the front but not what is directly in front of the car. So driving lights will fill in the very front to the beginning of the headlights if not in the headlights beam,
Fog lights color yellow is only a filter of "WHITE" so if you think it cuts through fog, think again, it is a sign of Danger, so to speak, so driving with them on all the time is just not cool, but when it is foggy it will warn you, or should I say others.
So white fogs lights, will be acceptable. And turning off any fog lamps in fog, will be the wisest choice.