The bluer the light, the more glare and reflection you get in bad weather, rain, fog. Best lights for rainy and foggy days are the yellower ones, not the blue ones. You can see the road much better with the yellow lights when it's wet.
However, the slight blue ones seem to work well on dry days as high beams, they really light up road reflectors and signs.
On my Subie Outback, I have 9005 Silverstar Ultras as high beams, H-1 Xtra-Vision as low beams, and I'd like to get some gold or yellow 9006s for the fog lights. Where should I look for those?