The fog light can be white, it just makes the light slightly pink-ish, I did 2x MOT's with it however and never failed. Red makes more sense though. Remember, white light is a mix of red, green and blue, your then pushing this through a red lens which will filter out all of the green and blue light anyway so you may as well buy a red bulb!
Yes, all external bulbs are wedge (aside from the headlamps) as far as I know. Mostly W5W's or T20's.