Safari 5 introduces the Safari Reader feature, for selecting article bodies to make reading and printing easier. I started looking around for where this new Reader functionality lives to see if it was customizable and I found that it is.
There is essentially a built-in CSS file with a tiny bit of Javascript located here:
/Applications/Safari.app/Contents/Resources/Reader.html.
You'll need to control-click on the Safari application icon and select Show Package Contents to navigate to this file, and a text editor (like TextWrangler) that can open and save files owned by root.
After backing up the file to Reader.html.bak, I changed this bit:
.page {
width: 658px;
margin-left: auto;
margin-right: auto;
margin-top: 10px;
padding: 45px 70px;
color: black;
background: white;
border: 1px solid #c3c3c3;
position: relative;
overflow: hidden;
-webkit-transition: height .5s ease-out;
}
to:
.page {
width: 658px;
margin-left: auto;
margin-right: auto;
margin-top: 10px;
padding: 45px 70px;
color: white;
background: black;
border: 1px solid #c3c3c3;
position: relative;
overflow: hidden;
-webkit-transition: height .5s ease-out;
}
It displayed as black with white text!
Mac OS X Hints
http://hints.macworld.com/article.php?story=2010060813435933