Although from state to state there are minor differences, here is the basic rule:
FRONT: Legal Colors
White (HID's are NOT BLUE, they are white.)
Yellow
Orange
REAR: Legal Colors
Red
White
Orange/Yellow
I personally despise people who just install white/blue bulbs for the turn signals so that when you turn it on, it lights up WHITE or BLUE. You're askin to get into an accident. Yeah, that white blinking light next to your headlight really is going to help others see what you are going to do.
I think it is okay to have the lens any color you want when the light is not lit, but when it is lit, the front turn signals should be orange.
I think white/blue rear turn signals are unsafe also. Especially at night, your white turn signals blend in with the headlights from the other car. While back, my buddy rear-ended a riced out civic with white turn signals, and the CIVIC got a ticket,

because he claimed that he couldn't see the white blinking turn signal. It should be RED or ORANGE!!!!!
And please don't get me started with, "what is wrong with being unique?"
There is nothing wrong with being unique. But there is something wrong with making your car unsafe.