FYI, the bluer/whiter the light, the more it scatters (simple physics). The more it scatters, the less returns to your retina - read: less seen. Yes white items show up nice and bright, but at the cost of EVERYTHING else on the road.

Finally, whatever you do - NEVER - buy a tinted glass envelope (aka bulb). Yellow tinting is ok - and in fact, I'd bet that is what is OEM on our cars. When I had a 1998 BMW and HID's just started there, BMW had added the yellow envelope to make the light less blue - and more focused.

So blue-bad, but pretty.