I dunno why but I have some very clear memories from a young age (4 or 5) of looking out of the living room window in my parents house and seeing the sky in a strong shade of orange in the late evening. I've often wondered why I don't see that nowadays. I thought it may be the sodium street lights or pollution through the clouds (there were factories with big old chimneys a bit behind our house). Maybe its my eyes getting less sensitive over the years and children still see orange night skies! I dunno, its a nice memory though :]