Yeah, that and it seems kinda silly to use white led's and just use plastic shades when white led's are about 20 times as expensive (about a buck if you order in bulk, as opposed to 5 cents for red or green). As for the blue led's, I say go for it. Who cares if you'll reduce the life of the oi by 10 years? It'll go out in style ;-)
You can try getting a 2v, 20mA blue one
here. I bought these for my case mod, and they're fine. If you could find a place that sells small quantities for under 3 bucks, though, I'd definately like to know.