The free time afforded me by the summer holidays here in New Zealand - without doubt the most splendid aspect of being a teacher - has provided an opportunity to update my Web site, and I've been converting it from static HTML to WordPress (that's a topic for a separate article; it was fun and not as hard as I had anticipated). I poked and prodded at style sheets, and was bothered by the colors I was seeing on the monitor of my slightly aging iMac. (And yes, it was a little freaky that this came on the heels of reading Joe Kissell's article "Solving the Photoshop Elements Color Shift Problem," 19 December 2009 - that was, however, an entirely different situation.)
A visit to my site will show you that I had placed a brace of sidebars in my design, and I had picked out a rather delicate shade of grey - #F0F0F0, if you will. But on my iMac's screen, the grey of these sidebars was an unmistakeable, undeniable white. I pulled out my not-quite-as-old MacBook Pro and opened the same page; the sidebars were just the shade of grey I had hoped for. I looked on my wife's iMac - she, being an actual designer, gets the newer machine, one of last year's iMacs with the glossy screens - and saw the same thing that my iMac had displayed. I took a look on my Mac mini's Cinema Display. Grey. I looked on my iPhone. Grey.
I was most baffled at this stage, so I decided to try enlisting the help of the TidBITS Talk mailing list, the folks there being a highly knowledgeable, helpful and just generally all-round groovy bunch of kids. Everyone - and over a dozen people were kind enough to take a look at my site and report back to me - said they were seeing grey (many of them were unable to spell "grey" correctly, but I overlooked this). One person did simply point out that my XHTML was flawed, but I blame that on Dreamweaver and WordPress.
So what, then, was the problem? Clearly the issue wasn't with my site (XHTML issues notwithstanding). As far as I could tell, it was a hardware issue, but what was flummoxing me more than anything was the fact that it was an issue common to the two iMacs, but to, as far as I could tell, no other machines. In utter desperation (and, let's face it, it takes desperation to fire up Windows), I launched Parallels Desktop on both computers. Internet Explorer 6 on the laptop showed the desired shade of grey but displayed the same page element as white on my iMac. My flummox capacitor was, at this stage, redlining. I decided to use Art Directors Toolkit (a highly useful utility, albeit one that doesn't believe in apostrophes), and found that both my computers believed that they were displaying #F0F0F0. It was increasingly apparent that the issue was with the individual computers; why, then, did two quite different computers have the same problem?
I searched, as best I could given my compromised Internet connection (see "Paying by the Bit: Internet Access in New Zealand," 15 January 2010), for news of video issues related to the iMac. The computer in question has an ATI Radeon X1600 graphics card; I could find no reports of issues with the X1600, or indeed driver updaters for the card - that's the kind of thing that Apple usually incorporates into an update to Mac OS X itself.
I went back to my Mac mini, took a screenshot of my site in Safari, copied that file to my iMac, opened it in Photoshop, and, again, saw white. This was, quite evidently, a problem with my iMac. I opened a blank document in Photoshop, and painted #F0F0F0; I saw white. I then opened a random selection of photos, and noticed that they seemed curiously posterised. I also saw that the colors in Photoshop's color picker didn't transition gradually from white in the top left corner to black in the bottom, the way they should; instead, any luminosity value above about 90 simply showed up as white. I buttoned in my favourite shade of grey; it was firmly in white territory.
I decided that I was fighting a losing battle, and went back to working on the mechanics of my site. I noticed, as a bit of additional freakiness, that when I was working in programs like Fetch that use alternately blue and white backgrounds for list items, the majority of a window would have a plain white background, but if I happened to have such a window in the background behind a foregrounded application, then the foregrounded application's windows would cast a shadow - and, in that shadow, I could see the stripes of the background window. And, oddly, my wife's iMac, which, you'll remember, is of an entirely different vintage, exhibited the same behaviour.
Back I went to the TidBITS Talk list. Many people suggested re-calibrating my display; while I was grateful for the time everyone took to try to help me, at this point it was like calling an ISP's tech support and being asked "Is your modem plugged in?" I had re-calibrated my iMac's display about half a dozen times, to absolutely no avail other than to learn that trying to spot that little Apple logo on a stripey background is intensely annoying after a while.
But then I got a reply from the truly brilliant Paul Durrant: "Check in the Universal Access control panel that the 'Enhance Contrast' setting is at Normal." A quick trip to the Universal Access pane of System Preferences - my first, I believe, since the days of Mac OS X 10.2 Jaguar; I'm fortunate enough not to need its features, so I've not opened it, as far as I can remember, in a very long time - revealed that the Enhance Contrast slider was, indeed, slidden one notch to the right. I dragged it to the left stop, and felt as though a veil had been lifted from my eyes.
I kicked up Safari, punched in my site's URL, and - mirabile dictu! - it displayed perfectly. I opened every page on the site, just to revel in the delights of medium grey. I opened another random clutch of photos in Photoshop; I was reminded of the day I got my first pair of glasses and could suddenly see properly again.
The mystery lingered, though. How could I have activated enhanced contrast, if that control is buried in a part of the operating system that I usually have no need to use? The answer, I suspect, lies in the fact that this feature can be activated using a keystroke combination - Command-Control-Option-period increases the contrast; the three modifier keys with a comma pull it back. (Try pressing the keys repeatedly; it's an interesting effect. But be sure to reset it in the Universal Access preference pane once you're done.) Once Paul's solution appeared, it was suggested that an application that involves a lot of convoluted keystroke combinations might result in features like Enhanced Contrast being accidentally invoked. But I'm not a big gamer, nor is my wife, so I don't think that's the issue.
But my wife has a cat. (We both have a dog; the cat is hers.) Cat has a tendency, as cats do, to wander across my desk. Among the many annoyances this results in are the unplugging of hard disks, the scattering of assorted kit and, I now strongly suspect, the triggering of unnecessary actions through - I can just picture the little bugger doing it - a back paw pressing down on three neighbouring keys, and a front paw stretching out and pushing the fourth.
My computer now behaves, the cat is banished from the office, and I owe a huge thanks to everyone who tried to help me, Paul Durrant in particular, who actually identified the issue. Now I'll see about fixing the XHTML...