Since there seems to be a thirst for knowledge (or at least for information), a few minutes of digging around on the web has produced this (in French):
https://www.defense.gouv.fr/actualites/articles/le-saviez-vous-des-phares-jaunes-dans-la-nuitThe salient points (in foreign accented English, with some
personal comments ):
- the source is a publication on the (French) Ministry of Defence website (
given our record in our most recent wars, not sure one should really give them too much credit)
-
the true origin of the (past) yellow colour on French headlights is unknown (today)
- one theory is that this was decided shortly before WWII to help identify German vehicles at night;
either some already knew the probability of having German vehicles on French soil was higher than the reverse, or this is one more nail in the coffin of superior French strategic thinking (Maginot line, cavalry to counter tanks, etc.): it would have worked just as well to identify French vehicles on German Lebensraum- another explanation, which is given a little more credit, is a paper or talk given in 1934 by or to the French Academy of Science (
an official body or collection of high-minded older guys with some scientific credits to their name who -collectively- don’t seem produce anything worthy of news lately, ie as long as one can remember, while their distinguished colleagues from the French Academy -note the absence of any other qualifier- at least produce a dictionary of acceptable French terms), that ‘observations by users (
does not say drivers!), and more specifically by those with a scientific education (!!!), shows that yellow light produces less glare (than white), and that the (human) eye readjusts faster to the dark after an encounter with yellow lights than white; yellow light also produces less glare from reflections on fog and/or raindrops,
seeming to produce higher contrast and to reduce eye strain’
(not published in this priceless article):
- I have a scientific education, I am an older guy without any scientific credits attached to my name, I am French (nobody’s perfect), and I agree with the second statement (and therefore will seriously consider applying to become a member of the French Academy of Science)
No information on rear yellow parking lights. A subject worthy of examination for my future life as a member of the Academy…