a black male runs into the doctors, the doctor asks the man whats the matter.. the man says i can't stop running. the doctor stops and thinks about it for a moment.
the doctor goes to the cupboard and grabs a cup of powder, then he puts 3 lines of the powder on the table. the docter tells the man to sniff it up. so the man does what the doctor told him to do, when he's finished he asks the doctor "jeez thats some good crack, what is it?", the doctor replies "Omo, guaranteed to stop colours running!"