The big problem with off-black text is that the designers who advocate them rarely test their sites on monitors that are like the ones the consumers actually us

The big problem with off-black text is that the designers who advocate them rarely test their sites on monitors that are like the ones the consumers actually use. Something like 90% of the people looking at your website will do it through a monitor that has a crappy TN panel and an even more crappy backlight. Designers tend to gravitate towards good IPS panels because their colors are much more lifelike -- but this means that the designer never sees the site like most of his users do. If you do web design you absolutely have to own a 2-3 year old TN panel with a CCFL backlight, and use it on stock settings, simply because that's what your customers use. #000000 on that is usually equivalent to #303030 or something on a good monitor. And #303030 is indistinguishable from your background color.