I posted this elsewhere, but here is my Phonak report when the aids were returned (5 yr warranty) after 3 and 2 years of age for high battery drain.
The older aid: Replaced electronics, housing, receiver, mic protector (filter), dome, and label. Also a general clean up.
The two year old aid: Replaced electronics, receiver, mic protector (filter), dome, and label. Also a general clean up.
The older aid may have been replaced completely but clearly the right one had the original case.
Colourwise, my original choice was champagne which is a good colour match for me.