Colombians tend to be very expressive while talking; they use their hands and arms quite a bit.  In formal and business environment touching is not usually accepted, but it can be more common among friends and family.

Touching is usually used to show a feeling (a hug, a kiss, a caress) or to get the other person’s attention or if you want to reinforce a special point.  You might briefly touch the other’s arm or shoulder and in few cases the knee, if you are sitting close to each other.