yellow lights are good for fog, snow, and rain.
there is also a difference between fog lights and driving lights. i personally like driving lights, but i usually get a bad glare in fog and have to turn them off. driving lights project a long and narrow beam as where true fog lights project a short and wide beam.
if you are mainly upgrading for fog, try out a 55w fog light (as in replacing the whole assembly).
Some good places to try are checker and walmart. if you are completely serious about the yellow light, i'm pretty sure piaa makes some ion yellow bulbs.
PIAA’* patented Ion Crystal technology is a great way to improve your visibility in inclement weather. Ion Crystal puts out an amber/yellow light that is less reflective than white light thus greatly reducing the amount of glare in extreme fog.
Single Pack 13555
Bulb Type 12V - H3
Wattage 55w = 85w
Technology Ion Crystal with XTRA Technology
hope this helps
2004 Torch Red Coupe
2001 Pontiac Bonneville SSEi - 103,000 miles - Galaxy Silver - Daily Driver
1994 Pontiac Bonneville SE - 209,000 miles - Light Gray Metallic - SOLD