Your most comfortable reading colours depend on who you are (or: how accessibility is a tricky business)
I’d changed the foreground/background combination on this site, which had been dark grey on white for eight years, mainly because I’d liked this piece on how the web became unreadable, which argues that there’s nothing wrong with a ‘crisp’ black on white for reading from a screen (and that true black isn’t true black anyway). At the time of writing I’m
#000 on a creamy
#FFFCEB (or washed yellow, according to Tachyons).
I’d also read something on the work site about how readers with Irlen syndrome can find a white background stressful.
The thing is, it seems more people prefer dark gray on white to black on cream:
Participants without dyslexia tend to prefer color pairs with a higher color and brightness contrast while people with dyslexia read faster when color pairs have lower contrasts. For instance, the color pair which was the fastest to read by the participants with dyslexia was black & creme… Luz Rello—Text Customization for Readability Online Symposium
And Marks himself appears to argue for this combination. In other words, you can’t get it right for everyone; instead, you’re better off simply avoiding the obviously bad and erring towards what seems the more obviously good. Something dark on something light, a big font size (although some readers don’t like it too big).