I have observed while driving at night the yellow marks on road seem white. What I understand is the color of an object is the visible light wavelengths it does not absorb. In other words the yellow line does not absorb yellow light.

The head light of my car is normal and thus is slight yellow light. So from my understanding the color of the line should not really change and still be yellow.

Can somebody confirm the same observation (or is something wrong with my eyes) and tell me the reason.

  • $\begingroup$ Which country? I would imagine that some jurisdictions add things to the paint that may affect the answer. Ground up glass or other reflecting material added in the USA might cause more of a white appearance under some conditions (possibly). It could also just be that there isn't enough light reflecting back to activate the color sensors in your eyes and you're left only with the gray-scale sensors (which would make this a biology question and not a physics one). $\endgroup$
    – tpg2114
    Dec 30, 2014 at 12:40
  • $\begingroup$ Well I am from India. I observed this on a highway where the yellow paint did not seem to be reflecting. I know for a fact that the pain was manufactured in Germany. Also I do not think it is due to lack of light as I could very well make out non yellow objects some times located a bit farther from the yellow light. $\endgroup$
    – chandings
    Dec 30, 2014 at 12:46
  • $\begingroup$ They don't to me. Maybe it's your color perception or night-sensitivity? $\endgroup$ Dec 30, 2014 at 12:48
  • $\begingroup$ well then i guess the whole question was moot. Thanks anyway. $\endgroup$
    – chandings
    Dec 30, 2014 at 12:50

1 Answer 1


Cold hearted orb that rules the night,
removes the colours from our sight.
Red is grey, and yellow, white,
but we decide which is right,
and which is an illusion.

$\qquad$Graeme Edge

The cones that give us the ability to see colors begin to shut down under low intensity conditions (mesopic vision) and completely shutdown under very low intensity conditions (scotopic vision). Colors are muted or just not visible at night. Human vision is limited to shades of grey at night.

You would be able to see colors by the headlights of your car if your car had ultra-bright headlights. You would also die because drivers of oncoming vehicles cannot see anything but your ultra-bright headlights. Most countries regulate how bright headlights can be. Those regulations keep lighting conditions in the low mesopic range.


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