Re: How is ear wax produced, what accounts for its color?

Ear wax is produced partly by sebaceous glands of the skin lining the ear 
canal and also by specialized glands called ceruminous glands in the same 
area.  It seems to be a mix of shed skin cells, fatty acids, and 
cholesterol.  Like the secretion of sebaceous glands, it probably functions 
as an oily coating to prevent the dehydration of the skin and eardrum 
within the ear (see an article by I. Okuda in Journal of Otolaryngology, 
vol. 20, p. 212, 1991 "Organic composition of earwax").  Actually, the 
secretion of fatty molecules by skin glands such as sebaceous glands is not 
a trivial function.  It is stimulated by stress hormones such as ACTH and 
causes the skin and hair to become oilier.  A genetically altered strain of 
mouse cannot respond to stress hormones by secreting these oils.  When 
these mice are dunked in water, their dry hair cannot shed water like 
normal and the mice can become extremely cold (see a review article in the 
journal Physiological Reviews, vol. 80, p. 979, 2000 "CRH and POMC 
involvement in the cutaneous response to stress" by A. Slominski).