I think I remember it said that the ones with thicker claws tended to be more venemous.
Although I cannot provide a specific identification for your specimen, as a rule of thumb, species having a combination of relatively slender chelae ('claws') and thick tail have stronger venom and thus are more dangerous than those with relatively thick chelae and a slender tail. The most dangerous species in Colombia belong to the genera Centruroides and Tityus; you might do an image search on those.
A subsequent identification was Chactas vanbenedenii. May be endemic to Colombia.