You say "tennis shoe" in your post, but I don't think a tennis shoe, per se, would be a good choice. Depending on your foot type, a good running or walking shoe would be the best. If you are going in the summer and looking for a good sandal, some mentioned here are Merrill, Nike, Birkenstock, and Keen. You can save money by ordering online, but try some on at a local store first to get an idea. Research first before you order online, then you won't have to worry about returning them.
As far as the Crocs go, I have a pair of the solid navy ones, and with jeans, they don't look much different than any other pair of clogs. I have huge feet, so the bright colored ones are out of the question for me.
Also, I saw the red-haired chef from the Food Network - Mario ?- wearing orange Crocs the other night.