It uses a #881 27W bulb. Not very common, but most parts stores carry them. I was able to find yellow ones online. I figured since they're so useless as a fog light, they might as well look good to other drivers ;-)
Funny, I just spent some time looking for replacements for my 2014 SXL. The OEM are a little too yellow for my taste especially with the HID's on. I picked these up yesterday from Amazon, "Nokya NOK6521 Arctic White Pro Halogen Headlight Bulb" for $15. I will report back with how they look.