I hear this all of the time, especially in reference to photographs. I can make a photo look completely different on my monitor by adjusting the color balance, saturation, contrast, and brightness. So when I have a photo that looks good on my screen, there is no way to know how it will look on someone else's. In some ways the net is much better getting images to prospective customers, but there certainly is a larger margin of error than sending prints to them through the mail.
Plus some monitors will interact differently than others when adjoining pixels are different colors. Then there are video boards themselves to throw yet another wrinkle into things. I had a computer when I worked for the state of Florida that was probably the cheapest thing they could find. Some sites were completely unreadable because of the way it handled colors. Anything subtle like light blue text on dark blue background was a completely lost cause.
I'll take a look at my color scheme and see if I can find something that works better. Hate to think no one would buy my animals because they HATED my color scheme on my site!
