It's cool but the amount of work...
I've done it and a few friends attempted it (one needed a new wiring harness when he burned something out soldering wise), but it's a real nuisance depending on how the area for your lights is spaced.
And get 4500-6000k leds since they look the most natural (unless they're under color then i'd say the mcd matters more than temp). One 5mm with a 30 degree lens will light up your entire interior at night lmao.
superbrightleds.com is my led store and they ship quick and cheap
Look under component leds.
I'd say the colored ones aren't worth the hassle.