Last week I posted about an issue I’d been having with the css generated by InDesign cs6. When I tested files on the Kindle for iPad and then Kindle Fire, I found that my black text wouldn’t revert out in the night theme. (It’s fine in iBooks and Kobo)
After some investigation I discovered that InDesign seemed to have changed how it expressed black in the css.
css generated from InDesign cs5.5 and cs6
This is the css generated from the same document – the one on the left in cs5.5 on the right cs6. Notice the color value. I hadn’t changed anything in InDesign except open the file in cs6.
Colour swatch options when creating stylesheets
This is the colour menu in the paragraph styles dialogue. You have a choice of black and registration to create black. Black is the default (at least it is on my set up).
Css generated using ‘black’ and ‘registration’
And this is what I got when I set up one style using ‘registration’ black and one using ‘black’.
Interesting…
Now I know how to fix it, it’s not a problem, but it had me scratching my head for a bit.
Edit:
Below is a screenshot of the night theme on the kindle mac desktop app and the accompanying css. The text styled as ‘body’ is not showing up and has a color value of #1a1818 which is what InDesign has generated when I used the epub export dialogue. The other text has had the css edited in Dreamweaver to colour:inherit and no color value.
kindle for mac black screen and css
Three Wishes Books 
The color Registration is a special one only used for print projects. It’s made up of 100% of each of the four process colors (Black, Magenta, Yellow, and Cyan) used to do full-color printing. It’s supposed to be applied only to certain objects that fall outside the trim area like crop marks and registration marks, so those elements show up as 100% in color separations.