When I bought my LED festoon bulbs to replace the incandescents in the door switched interior lights, I made the mistake of buying cool white instead of warm white. The light cast by those LEDs caused my friend to label my van "the morgue".

But no more, thanks to a lighting filter.

http://shufti.wordpress.com/2011/11/23/vanagon-changing-the-colour-of-cool-white-leds/

alistair