>Ideally though pure white background should be avoidedI can buy into eye fatigue from the background being mostly arctic white (#FFFFFF) such as a fullscreen Notepad text editor. This can be especially annoying when one has a 31" monitor -- it's like having a giant 31" lightbulb shining into one's eyes.
However, I still don't see any evidence that the text color of #000000 causes eye strain.
HN'rs... try this:
go to "sarahwerner.net" (the webpage of this thread)
In Google Chrome press F12 for Inspector
Right-click on one of the grey paragraphs and select "Inspect element"
In the "Styles" tab, press "+" to add a new css rule
The new rule is "p { color : black; }"
In Chrome, it lets you use your mouse to click a checkbox to dynamically toggle that rule
You should also see that the values properties pane to toggle from "rgb(68,68,68)" to "rgb(0,0,0)"
(Modify those instructions for Firefox, Safari, etc.)
(Here's an animated gif showing what the F12 experiment looks like: http://i.imgur.com/mmfKIjW.gif
Keep in mind that GIF demo is 8-bit color not 24-bit so you must do the experiment yourself to get an accurate comparison.)
Experiment with toggling back & forth and see if you suffer the "eye strain" when it flips to #000000 that some folks are talking about.
Personally, I think #000000 looks more readable because even though the sarahwerner.net's background is #FFFFFF (pure white), it doesn't "feel" like pure white because she has large elements on webpage such as photos and screenshots. My guess is that the eye "averages" out the entire background to be a "light grey" even though the underlying RGB value is pure white.