i use to have blue bulbs on my rear license plate on my stock bumper and i got pulled over because they cop just thought my license plate lights burnt out... Plus i had blue reverse in at the time and it took so long getting out of their without reversing infront of the cop. A few weeks later cops waited at my college apartment parking lot and waited for me to reverse then busted me a ticket there.. So i don't use blue bulbs anymore except for my interior dome light.