I don’t really understand why you keep calling it ‘unreadable’ - I find it perfectly fine, much easier on the eye than black on white. It’s hardly low contrast. Are you suggesting that designers should always use maximum contrast, and nothing else? Can you really not read this text easily? It sounds a lot to me like you are inventing a problem which doesn’t exist (akin to your first link in the post above perhaps?)
they do that may be to get smart readers 
you can highlight it to read.
You call it “fine”, I call it “unreadable”. Both are our opinions.
However, the “unreadable” view is backed up by 400 years of print experience, 60 years of CRT experience, 10 years of LCD experience, the opinions of people who make their living off of usability, the opinion of my ophthalmologist, and by W3C and federal guidelines.
So far, the “gray is OK” view is only backed up by the opinions of some designers and one claim about an alleged, hyper-minuscule group of impaired users.
Google reveals many users complaining about gray text, they call it “unreadable” too. So far, Google has revealed no one who wants grayed text, except for “designers”.
There are several Greasemonkey scripts to reverse the gray plague. I have yet to see one that makes black text gray!
Anywho, thanks to this thread, I now comprehend why this scourge happened ("information cascade" and herd mentality) and have an easy way to make my sites better than my competitors. :)If you say so…
I have certainly visited some sites where the text was grey, and as a result I could imagine it might be difficult for some people to read. But the majority of websites use more of a charcoal shade - I agree with others that, against a white background, it is more readable than pure black, and is less likely to give me eye-strain if I read it for prolonged periods. Sometimes if I’m reading a lot of black-on-white I have to adjust the contrast on my monitor. That seems to be the majority view here.
When sites use dark grey rather than black, I often don’t even notice, the two shades are so similar, so I am very surprised that you find one easy to read and the other one completely illegible. If it continues to be a problem, it might be worth looking into a user stylesheet that you can use to override the site stylesheet on those sites where you need to.
On my personal site, I have a black background, and at first I used white text. I got sick of the letters burning into my retinas (I would actually “see” the faint images of the text for a minute or so after reading the page) so I finally switched to a light grey text and it was a LOT better. For me. YMMV, which is why I allow the user to switch style sheets and offer a higher contrast choice.
The problem with designing for “everyone” is that everyone likes something different.
Well it seems interesting to me that “MrMr”[URL=“http://www.sitepoint.com/forums/member.php?u=135872”] seems to be the only one citing any actual evidence. Everyone else seems to rely on the subjective “it looks better to me” approach, but do they only design pages for their sole use?
I have a fairly new 22" lcd monitor. The cheapest newsprint exceeds it in quality by far. I notice that newspapers tend to use black on white. If they need it for newsprint why would we not need it for monitors?
The whole topic is subjective here, there is no evidence. Any evidence will also be based on people’s opinions. I find it interesting that the majority of people here think that there is nothing wrong with it - I’d say that counts as a survey, and evidence for using it 
None of the newspapers that I read are printed on pure white paper. Most use pulp which, by the time it gets to me, is definitely an off-white colour.
I also find black text on an off-white background or grey text on a white background easier on the eye than the “maximum contrast” option of black on white.
Just my thoughts.
Rich
Evidence?? I would say MrMr proports to have evidence but I have yet to see any that is backed up by science.
As mentioned earlier newsprint isn’t white so there goes that theory however the reason you can take a shiny white piece of bond and slap black text on it via a printer for a high contrast good read is due to the fact that paper doesn’t contain a light source. White on a monitor is caused by your eyes being bombarded by light. It is more evident with a CRT because the light source is stronger than the backlighting of an LCD but none the less you can light up a dark room with an LCD showing a white background… Try that with paper 
I read studies about white/black contrast problems more than ten years ago and have always used a #333 or darker text on white or a #F7F for my white. I’m with Stormrider on this topic… There seems to be much ado about nothing.
If you use a dark enough gray, the contrast can definitely be more than sufficient. I don’t see how “gray” can be inherently bad, or pure black can be definitely good.
I just measured the contrast ratio for the standard greyish text in a post here, and it’s 13.29:1, exceeding the minimum recommended 10:1 for level 3 accessibility.
For a quoted block of text here, it’s 12.72:1, again exceeding the minimum.
This box I’m editing the text in is 18.66:1 and thus totally acceptable.
I also experimented on a site I’m working on just out of interest, and found that by changing the text to #333 (before I measured it here) on the existing background of #F6F6F6 gave a 12.33:1 result. It also enabled me to set h2 and h3 to #111 or #000, so they stand out, looking bold but without the thicker (and less readable) characters of a font set at bold.
So all in all, I don’t see (sic!) anything wrong with a little bit of grey here and there.
The artistically-designed type of pages with very similar shades of grey on grey are a different matter of course. I was recently on a site and it was only after several minutes that I realised there was a “cleverly”, subtly coloured grey on grey sub-menu below the main menu! Now that is BAD accessibility!
Nice… I particularly like the idea of varying the contrast to make h2, h3 stand out without thick bolding.
Black black black
Gray gray gray
^until doing that test, i didnt even realise the writing on this page was gray, do you have a problem reading this MrMr?
I find it very difficult to tell the difference when its not bold:
Black black black
Gray gray gray
but I have seen sites where the gray on white is something like this:
Gray gray gray
I can definately see this being a problem!
your test isn’t valuable, because the eye fools us with the surroundings of the text. Because you put #222 color beneath #000 color you will see the difference more.
if you do more spacing it will become less obvious
Another thing is the characters themselves, less of your space filled with characters is a big difference. So make the text the same
Black black black
Black Black Black
you see, even less visual difference
^ Actually shouldn’t that be done unbolded for less visual difference between the two?
I was just demonstrating how small the difference between the two are, although the gray is a little softer on the eye.
I bet some people veiwing this thread cant see any difference at all!
True enough and it would probably be even less of an effect on a white background.
MrMr, they are doing it just for a different look.
Period.
I do it with my site too, but I make sure it is just with headlines, and the text is much bigger, and, it is in Georgia font.
Gray, along with black, breaks up the monotony (same 'ol same 'ol) of a site, it gives it a bit of style.
Is this the answer you were looking for?
What about gray text on a black background, which antagonates the heck out of me. Last week I told a vendor to just send me a printed catalog; their web site was just black with faint letterlike scratches. It was of course a very “designy” site.
What are these people thinking? Especially when they think they want to sell you their product…
MP
PS: And Sony, you can just fix your black-on-black Voxengo plug-ins, too.