Maybe I'm the only one who's ever had this problem, but I've come across a few color discrepancies in my pictures as I take pictures on my camera, transfer them to my computer, and then upload them to the internet or send them to the printer. A few years ago I came across this color issue:

The picture on the left was my photo processed in Windows, then uploaded to Flickr. The photo on the right was the same photo downloaded from Flickr onto my desktop. Obviously the color differences are huge. The problem? The color management profiles, or ICC profiles, on my computer and in my internet browser were completely different. The question then is, which photo gets printed if I send the picture to the photo printing company? Well, in that case it will once again depend on what the color profile of the printer is. This is one of the headaches if your color management isn't dealt with. I found a good article online regarding color management on your computer. This webpage has a few test shots so that you can tell if your computer is correctly handling the color in your digital pictures.

In my example above, my browser was using the standard sRGB color profile, however XP was set to AdobeRGB (1998). Images produced in XP weren't correctly tagged. I could be wrong though. These days I have everything set to sRGB and then my monitor calibrated for color. Even then, I had set the color profile incorrectly in Lightroom and messed up a batch of photos printed at Costco.