When I did that at MAC, I couldn't find anything that looked any good on me. They didn't have the sort of red I wanted, which is a dark red with orange or brown undertones. All theirs seemed keyed to cool skintones.
Granted, I don't like the "help" I have gotten at the MAC here in Kansas City. Both times I have asked for eyeshadow reccomendations, I have walked out of there looking like I could scare a clown. Their makeup artists are very pleasant and like to play, but don't have a good eye for what people might want to look like on an everyday basis.