In addition to Greenler you should see "The Nature of Light and Colour
in the Open Air" by Marcel Minnaert. Minnaert was an astronomer, and
the original was written in Dutch, but the translation has appeared
under this title and also (in an older copy of mine) as "Light and
Color in the Outdoors". This is a wonderful reference for every
teacher of science, and an edition of it (which I haven't seen) is
available from Amazon for US$8.46.
Greenler's book "Rainbows, Halos, and Glories" is also very nice, and
I wouldn't part with my copy, but the Minnaert book is the classic,
and I couldn't bear to leave it unmentioned here.