Pilots require full colour vision

One of the requirements for a pilot's licence is that you can distinguish colours.. this is important because the left or port side of an aircraft, similar to ships, carries a red light and the right or starboard side of the aircraft a green light. 

This helps tell whether an aircraft is flying towards you or moving further away or is passing from right to left or left to right.. more important at night when your other visual references are impaired.

Click on this link to see if you pass the colour test.