Headlights

[Lynnieshell]

What is the point of headlights that appear to change colour depending on the reflection of the light in them. It seems to me they are dangerous more than anything - I often think there is a police car or ambulance approaching because they appear blue. Then within a couple of seconds they appear white/purple etc.

[Metaphysical]

I don't know if I would call them dangerous, but it is definitely annoying!! Also why are so many headlights sooooo bright! I am blinded by on coming car headlights a lot of the time when driving home at night. It's like they have their high beams on (but they don't). Damn irritating!

[rekstout]

It is more to do with the colour of the light providing greater definition (and therefore improving driver awareness) than the yellow light from traditional headlamps. The colour change thing is probably just a side-effect.

[KARL]

I think I am correct in saying that the effect you describe is caused by your seeing first the core of the beam of light emitted by modern halogen lamps, then as the oncoming car moves sufficiently for you to see mostly light from the fringes of the beam. The fringe light has a slightly different spectrum because it is more diffused - all to do with reflection, etc.