Cup Changes Color After It's Been Drugged...
Gamma-hydroxybutyrate (GHB) is odorless and colorless. But it's now possible to detect it easily. There are materials that change color when they come into contact with GHB. If you make a glass out of it, the drinker can...
http://www.neatorama.com/2012/12/18/Cocktail-Glass-Changes-Color-After-Its-Been-Drugged/

