god kills a kitten AND a puppy everytime you turn a neon on in a skyline.
although in the grand scheme of things you're only slightly more pretentious than wankers that run around with japanese learner driver stickers, so don't fret.
rear facing red lights are legal as long as they are turned on with park lights, as are foglights or driving lights in front. you can try and adapt this to neons if you want (I guess run a white-yellow one in front and red in the back) and try and pass it off as driving aids.
you can't have red or blue lights inside or outside the car while driving in a way that is visible from the outside so as not to cause confusion with emergency vehicles. this includes LED's, neons, CCFLs etc and any glow from footwell lights.
you can't have a purple light on your car unless you're a harbourmaster in certain parts.
yellow lights on the turning side are also legal as long as they are activated by turning signals.
that said, you'll find 99% of this forum and most performance forums will bag the snot out of you for putting em on your car.