Another option is to investigate "media queries" to see if I can display different imgs for b/w devices. (
http://www.w3.org/TR/css3-mediaqueries/,
http://epubsecrets.com/media-queries...le-devices.php and
http://epubsecrets.com/media-queries-in-epubs.php, page 60 of the AMZN pub guidelines).
And I finally got the Previewer working again. The joy of upgrades:
http://epubsecrets.com/fixing-kindle...x-yosemite.php
I'll check out the books you listed later today. Thanks again for the help and info.
(edit: it looks like a monochrome query is do-able.
http://www.w3.org/TR/css3-mediaqueries/#monochrome. Maybe two images, where the CSS rules display the appropriate img for display type. Must put on my Winnie-the-Pooh "Think Think Think" hat and ponder.)
-w