Your eyes deceive you, grasshopper.
The NHTSA sets limits to the number of lumens headlights in the US are allowed to emit. Sylvania cool blues are at that limit. HID'* must also be in order to be imported and sold here. The difference you see is NOT brightness. It'* wavelength of light. The human eye percieves them as brighter when in fact, they're NOT! The headlight manufacturers get around federal law this way......by using SCIENCE (lumens) against the human eye (blindness)......funny the regulations are intended to protect oncoming drivers.....it should be the way the human eye percieves this light that determines the legality, but that'* too 'gray'. The standard therefore must be scientifically backed.....and lumens can be measured.