If you were ok in Brazil then it is likely you will be ok in Colombia. In Rio it is well known you can't go to an ATM machine after dark and especially when not in a tourist area brightly lit. In fact walking down the street on Copacabana teen age gangs may attack you if you are wearing Gold or watch, camera etc. I never had a problem in Brazil but was well armed with what not to do.
I never had any such feelings in Colombia although I certainly arm myself with areas not to visit Bogota is a gigantic city and there are many areas that might not be safe just like NYC, Chicago, Mia etc.
Hire yourself a guide off of PlanetRomeo or Hornet to show you around the first night and have Sex . Then you are likely to be introduced to his friends who would like to make money and will not want anything to happen to you.
I know I stayed in the Hilton in Bogota and always registers my guests and since they had to present ID , they were likely to make sure nothing happened to me.