I ran a Blue LED dome light in my WRX when I had that...

I LOVED IT... I added a transistor/capacitor to the power source to make it fade in...

walking to my car at night when I'd push the unlock button the interior would just slowly light up and emanate blue... it was pretty damn cool.

that and things just look way sexier bathed in blue light.

but yeah that was just the dome light, it's only on when you open the door, the map lights were left white so you could see stuff... though I wouldn't do any reading under blue... tis good enough to find the key hole, or locate a CD, etc.


I will say though that the human eye has trouble seeing blue light... a little wimpy festoon bulb will be REALLY dim... you'll definitly have to go with some like what etlsport posted