I think it was a reference to the color scheme in the screen shot, not to the site itself. I find choices like dark blue and brown against black to be hard to read.

You've probably got a low-quality LCD with a bad color calibration, then, or else just a really bad contrast ratio or lots of glare. That color scheme doesn't seem to me to have any colors that would clash, even to colorblind and partially-colorblind people. Sure, it's a relatively low-contrast color scheme, but I think it would be generally harder to read if the contrast were really high. You shouldn't use much in the way of full-intensity colors when you have a black background.

It looks like it is a modified version of normal emacs highlighting for shell scripts to me; the colors are different from the defaults on my computer but not wildly so.