Originally Posted by tmax
It was in the mac section in a department store.
I know it's not what you want to hear, but never believe anything a salesman says to you. None of them (not even in Apple Stores) understand the products they are selling, and they almost always work on commission, so they will say anything to make a sale. Some stores might not be as brazen as others, but you should never expect a minimum-wage flunky to have the knowledge of a highly-paid consultant (or even of AppleInsider forum members.)
Do your own research before entering the store. Then sit down and try what you're interested in buying. If the store doesn't have a working demonstrator that you can use to test out your normal workflow, go somewhere else (or make sure the store has a no-questions-asked return policy).
Hopefully, you'll be able to get some kind of satisfaction with your iMac. If the store won't take it back, maybe you can sell it, or get an external (higher-quality) display for those activities that require accurate colors.