Hey
They are not only bright they use only 35 watts each! and they come in the correct color....well almost the lowest color i can find is 3000K but this 3000K is very yellow like what you would see in a fog light so i think it will rock. I don't know why no ones ever tried this.
As for the purple cfl, it's been around for a few years primarily in the UK. Haven't seen any one try them but they are suppse to have higher blue and red spectrums but i think they are not bright enough only a third of 6400K so i think light penatration will be a problem. I got them for free from a chinese supplier to try and test them. Just had to pay for shipping and he sent me 6 of them!.