The contrast is a little low for me, but I can still read it fine. I think a lot of the problem might be the amount of ambient light in the reader's room. My room is somewhat dimly lit.

I'd love to know this too: almost every article on HN has someone commenting about the contrast on some text. To me the difference between the black and grey is fine, and I wouldn't have even thought about it if you hadn't said anything.

I initially figured it was because of the MacBook Pro retina monitor is good, but I hear the same complaints from other people on the same (or similar) set ups.

Is it a world of difference between monitor calibrations, or human eyes, or both?!

The macbook pros tend to use more correctly calibrated colour than typical desktops with monitors, and typical non-apple laptops; This means that decisions made on non-reference monitors that have never been calibrated.. well, they can look completely wrong on a monitor with the correct calibration.

Get a Lenovo huey or a Colorhug, correct your monitor, and you'll see what I mean.

On the web, you don't really know what you'll run into. You should aim for a level of contrast so sharp that it borders on uncomfortable, so that when the contrast between your colour selections is less than you thought, it'll still at least be legible.

Got any reference for that statement? I often work with color in surveys so that would be super interesting.

Sadly only personal experience and rumour.

I work in an office full of Mac users, and I'm among maybe three people who don't use Macs for work at the company.

All of the non-Apple monitors in the company are not correctly calibrated and lack colour profiles (and are by default not configured correctly either).

I recently bought a colorimeter, and calibrated all of my displays(including my external displays); after doing this I realized that the colour on my monitors most closely resembled the default colour response on the MacBook Pros in the office.

My colleagues(who admittedly didn't understand colour calibration at all, even the designers) are under the impression that Apple profiles and calibrates the panels at the factory(and presumably ships custom profiles for the factory state of the panel).

I think it's probably cruder than that. It's likely that they ship one profile for an entire family of panels, which gets it closer but doesn't account for time and manufacturing variances.

Lots of things can influence text legibility. Different display characteristics, environmental factors, the font that ends up being rendered, view distance etc.

I read it without a problem and didn't even notice it, but after you said that: yeah, text should be a tiny bit lighter.