Be aware that the law in some areas may prohibit the use of red, blue or green lamps from the front of any vehicle unless it is an Emergency Vehicle and operated as one exclusively. Blue is usually restricted to Law Enforcement, red is for Fire & Ambulance , green is commonly an Incident Command Vehicle.
It's actually in all areas. FMVSS 108 governs. Headlamps must fall within chromaticity area of white. However, there are areas that are technically white that have sort of a blue look (light from a HID gas discharge source for example).
You'll have to make your own judgement. I'm not implying that you shouldn't mod, I just want to provide info to you so you can understand what is correct.