I wouldn't see any issues with red tinted fog lights, since they can be turned on and off. Don't think I would drive with them on, but no differently than neons. I'd see nothing wrong with park and light. Easy solutions if you still wanted to have them be functional legally would be to make covers or use tinted "static" covers that can be taken off and put back on whenever you want.
There are quite a few cars around here that run with yellow headlights and/or fogs, but that is an allowable color. Really depends on your area though. Here, I wouldn't drive with forward-facing red lights turned on. I have seen plenty of cars with colored halos/angel eyes in the headlights or fogs drive with no issues. A couple of sinister looking GPs that have red halos around on the forums. Hell, some of them have color change units so you could pick your mood or switch from street to show.
Check your local laws. I've heard that police depts. can also use DOT standards as a de facto standard even if it is not a local law. Not 100% sure if that is true or not.
I personally have 5000k HID lows/Halogen highs in my projectors (with halos) and am putting 3000k HIDs in my fogs.
