"But I frequently found myself to be the only gringo around and on the receiving end of some unfriendly stares."

Haha, I know too well what you mean buddy :D Happened to me many times in Medellin and Bogota. I later figured out that wearing a shabby hoodie helps a lot. It doesn´t make you look rich and even hides your "gringoness" :D Awesome shots btw, Colombian street art is a world class. I published a bunch of posts here dedicated to it. Top notch post! Too bad I don´t have any more TipU curation votes left today... Btw add the tag #oc next time (or you can edi it now too), that makes you eligible for curation by @ocd and @ocdb and they love to curate awesome trave posts like this one ;)