The victim was in a residential address at the back of a shop in London Road on Monday when the incident happened.
A four figure sum of cash jewellery and a mobile phone were stolen.
One man was described as white, between 5ft 6ins and 5ft 8ins tall, of very slim build and wore a long sleeved black top with a red design. He also wore a head and neck cover. The screwdriver he used to threaten the victim with had a dark red handle and was 12 to fourteen inches in length.
The other man was also white, around 6ft tall, of slim build and between 35 and 38 years old. He was clean shaven, with dark hair, and wore a light long sleeved button up shirt, dark navy blue trousers. He was carrying a large knife.
It is believed a third suspect was present during the incident.
Detectives are also looking for a dark coloured Audi A3 on a 14 plate believed to have been used by the suspects.
Anyone with information is asked to contact Dc Trevor Clarke at Colchester CID on 101 or Crimestoppers anonymously on 0800 555 111.