I have the Diamond Vision bulbs as fogs. against my Xenons they still look slightly off colour but way whiter than the OEM bulbs. So I guess it'll be the same for headlight bulbs. Unless you have the R8 with full LED technology you won't get the light beam cast ahead of you nor stay on the right side of the law.
^^^ they'll likely be **** IMO, the blue filter reduces light output too.
I bought some OSRAM nightbreakers off ebay for under £15 off ebay; they are definitely whiter than normal and seem pretty bright, they do impress every time I turn the lights on for halogen lights anyway.. They do have a very small filter on the bulb but with a gap around the filament.