Guys, ya'll are missing the point!!
If the roads are that foggy...STAY HOME and have a brew! From my experience driving in Europe...5 foot visibility fog, near white out snow storms, day and night, I tried both yellow and white "fog" lights.
I have read all your arguements/points and all have a bit of truth and a WHOLE LOT of personal preference.
For me, the yellow DID appear to have less glare...but then I realized it was just a dimmer glare--but a glare none the less. lol
As for the white fogs, they seemed to work as good as the yellows...with a brighter glare...are y'all seeing the recurring theme....FOG = INCREASED GLARE, period.
Now, that said...I'll most likely get flammed based on the responses I have read so far, so....get what you believe will work for YOU. For me, yellow fogs mounted higher on my runner worked good. On my wifes car (Volvo), white lights worked equally well closer to the road surface.
In my opinion, el cheapos fogs from (insert your favorite discount store here) worked just fine. I had a set of Hellas I bought from the BX. Some of my friends had PIAAs, which in the conditions that I observed, worked no better than my 40 dollar Hellas (again from the BX).
So, in conclusion to my lengthy reply, yellows APPEAR to work better up high and whites APPEAR to work better lower to the ground. Buy what will work for you and don't be influenced in buying high dollar items merly for keeping up with the Jones. In driving in fog, drive no faster than is prudent, which almost always is NEVER the posted speed limit! Be safe!
Now, if long range driving lights are what you need (as I do in driving on dark highways) and you need to slice through the darkness, INVEST a bit of money on QUALITY lights. The el cheapos will not cut it (no pun intended!) been there, done that. The lens design and light output are far inferior to the QUALITY light of your choice.
Happy Holidays!