Do you want it for looks or to project out? I had a yellow bulb in my stock housings that looked good but had no function. I replaced the entire housing with Diode Dynamics SS3 Sport and they put off an incredible amount of light. (Very precise and non-blinding, and street legal.)
If your original housings are junk, you might consider these more expensive options because you’ll have to spend the money anyway. I had installed Sea Lights in mine that were bright yellow. They are effective, but I prefer the light that a more amber bulb puts out. After I installed driving lights that can do amber, white, or amber/white, I saw no need for the yellow lights anymore and put some 60000K sea lights in to match my headlights.
Yellow fog lights. Like Prime said, they work better in fog. Can confirm. They also work better in the snow.
The amber color I prefer. Drove home in a near white out blizzard one night, and these were great, at least for my eyes. You can also see the whites I put back in the stock location. Both work great. And I like the options I have. The amber seems to not blind people as much as bright white.
That was one of the first things I did with mine. The OEM lights were dismal at best. Plus, the housings were trashed from years of sandblasting out here in the desert. I have a how to on replacing the housings on the newer in the 2nd generation DIY area here.
I've spent a small fortune on my front lights. I just installed Stage 1 Headlights from HIDprojectors.com. I wanted to keep the stock look as my front end is blacked out and I like the contrast they give to it. I then added Lasfit 4157 blinker led lights to them. I put SS3 Pros (yellow) from Diode Dynamics in my off road lights. For fog lights I went with Alla lighting fog light bulbs. They are yellow too and are not overbearing.