Wanting to change stock yellow foglights to white lights

Were yellow fogs ever stock?

 

OP is saying that the "warm" 4500K color output of the halogen bulbs is "yellow" compared to the "white" color of the IMO bluish color output of some HIDs and LEDs that are in the 5000-6000K color temp range.

IMO, yellow foglights are exactly what you want for better contrast on wet roads and foggy conditions. At night, when the roads are wet, white light will glare off the road, yellow light gives contrast to the road so you can actually see potholes, etc in the road surface. I intentionally put yellow bulbs or vinyl film over my foglights on all of my vehicles for that reason.

Posted via the PriusChat mobile app.

 

Take a look at USA made LEDs from Diode Dynamics
Automotive LED Replacement Bulbs & Lighting Upgrades

 

Amber fogs was a big deal in the 60s and 70s I still like the looks of them better, but I'm old.

 

Those will probably be more cosmetic than functional as far as light output.

Posted via the PriusChat mobile app.

 

Did you look at the DiodeDynamics link I quoted above?
That would have answered your question

Fog Light LEDs for 2004-2009 Toyota Prius (pair)

• Direct replacement for Toyota Prius fog light bulbs
• Modern LED output with long life
• Plug and play, no modification with factory 9006 bulb size
• Available in multiple brightness levels

 

The K value is degrees Kelvin color not necessarily brightness.
You can call diode dynamics and enquire about brightness options.

 

As many States require you to have your headlights turned on when it’s raining, Gen2 Prius’s don’t have stock DRLs and using the Fog lamps in the rain is useful, so that would be a problem.
Another Prius design flaw.
Did they ever replace them under warranty?

 

Yep, stock lights are crap and now another reason not to like them.
But DiodeDynamics see link in prior post, #14, above, offers high output LED fog lamps. Pricey but they are a USA manufacturer and come with three year warranty.