I am working on a series of books now (web blog type) where the author chose to use font color for different speakers/meanings. It works well when you have a darker background but some of the lighter colors are almost unreadable if you have a white background so I had to force the background to a darker color using the <body> tag.
CSS:
Code:
body {background-color:black}
Normally I would change the font to some other method of differentiating the speaker, but the color actually helped in the story telling so I used the body background-color work-around.
It worked fine on my device, but it is definitely NOT recommended on an e-ink because it tends to make it almost unreadable. Maybe look at some media queries to handle this.
Also, I'm not sure if Amazon has a rule against putting a color in the <body> like they do with the font??? You may want to check that as well.
However, even if you put that styling in there the device/app might not honor the publishers CSS... some of them ignore it completely in favor of their internal styling, some will ignore parts of the CSS. If you want to "force" the background-color you can put it as an inline style (not something I normally recommend doing...it makes my tummy curdle just thinking of it...) on just the body/div/p you really need using:
Code:
<body style="background-color:black">
<div style="background-color:black">
<p style="background-color:black">
....please use inline styling rarely, if ever...