I have the black Crocs heels and as far as heels go, these are pretty good.  They (the black at least) look very nice and people don't know they're Crocs unless you tell them.  I've been complimented on my cute shoes several times (without people knowing they're Crocs).

I've worn them without socks or hose, so if you're not a hose-wearer, be aware that they'll start "squeaking" on some of your steps after you've had them on a while, or your feet start sweating.  These can be worn with pants or skirts and have a classic, yet up-to-date, look about them.