Do not wear heels. As a pharmacist, you're not going to be wearing heels. Show them you make good decisions as you may be on your feet a lot if they do tours or even just walking from one place to another. Sure, some may, but they'll regret it and your feet wont' hurt.
My interview is next week. I'm wearing a black pants suit, a pale pink dress shirt underneath, business professional (but really comfortable) black shoes. I've also heard Navy or Gray can be appropriate, but opted for black.