You're on the right track with the ColorSync calibration procedure in System Preferences. However, a lot of the LCD monitors these days are so darn bright that it might not be practical to set them to maximum brightness. Although it sounds like at least part of your problem is that your monitor brightness is set too low, if you can't get a decent calibration at the max settings, simply set the monitor to something reasonable and go from there.
Try the calibration procedure in advanced mode. As for gamma, it shouldn't necessarily be 1.8 or 2.2 or any particular magic number. In other words, set it to what it needs to be set to as indicated during your calibration. Make sure you go all the way through the calibration before you panic, as it's not done until it's done and things will change as you go. It may take you a few tries to get it the way you want.
Visit COLORRIGHT to get the colors right in your digital slr.
Thanks very much for your time ! I will give the advanced ColorSynch mode a try as soon as I get home.
A temporary (and certainly not perfect) solution that I finally used was to set the controls of my LCD monitor (at home) so that the processed images look as "bad" as they do on my CRT monitor (at work) and a couple of other monitors on PCs running windows. I then had to re-process my JPEGs and now they look on my Mac almost as they do on PCs.
Thanks again to everyone that helped, I might post an update if I manage to make ColorSynch work.
Linear Mode
