Clear fog lights are available as the first option under lamp. U-H9415 (Clear).
They can also be found as 692-2 clear fog lights with standard wiring kit
http://www.unityusa.com/692-2-4-x-6-Rectangular-Clear-Foglights-Pair_p_207.html
and as 592-2 clear fog lights with deluxe wiring kit.
http://www.unityusa.com/592-2-4-x-6-Rectangular-Clear-Foglights-Pair_p_221.html