Ok, I've been fooling around with this all day and finally decided to at least try a test case. (Certainly the code for the main book is pretty sloppy, but I at least wanted to make sure what I was going to do worked before I spend many hours "fixing" the whole thing only to find out that wasn't the (only) error.
I've attached a very simple azw3. I started with word (html), generated an epub using toxaris, but everything was black and white (looked to me like the "generate epub" stripped any colors and made everything black and white).
So, I took the html, uploaded into Calibre, converted the html to azw3. The resulting azw3 shows is color in Kindle Previewer and Calibre, and again it is black and white in the actual Kindle. No errors from Kindle Previewer,
http://validator.idpf.org/application/validate, or Calibre "Check Book".
I even sent it to the Kindle via calibre and also just using windows explorer folders and USB. Neither worked. Any ideas what might be wrong now? Thanks.