I looked great to me - perfect and very readable. But I didn't consider the older eye, or other eyes, which don't let in as much light.
Hopefully the author will learn and adjust. Contrast is good.
A lesson for the designers among us: almost no-one is viewing your site on your 5k iMac screen. Design accordingly
But I don't think the colours them selves are absolutely unusable together, I think the combination of the colours and the font weight/size is really the issue (although that could be less the case on a retina screen).
It also doesn't help that I'm viewing it on a older monitor with poor colour control (particularly with contrast).
The icon sometimes doesn't appear in the address bar though (apparently because Firefox is unable to identify where the text content is in the page.)
I've also found the extension - Open in Reader View [1] to be useful for those situations.
[1] http://firefox.add0n.com/reader-view.html - Firefox, Chrome and Opera
https://chrome.google.com/webstore/detail/high-contrast/djcf...