Besides the unreliability of color vision tests for pilot candidates it is also often discussed, how well your color vision has to be to acquire a pilots license.
Usually you have to have normal color vision—or at least almost perfect color vision—to pass the medical tests on the way to get a pilots license (color vision information for pilots). Any type of color blindness is a no go.
Not everybody agrees with this color vision standards for pilots. While some argue that perfect color vision is required to manipulate all the complex cockpit instruments correctly and see the warn and signal signs for aviation, others say that you don’t need to have perfect color vision to be a good and most important securely flying pilot.
The National Transportation Safety Board (NTSB) wants to find out more about how color blindness affects pilots. They started a major study and researchers are determining whether color identification difficulty develops, worsens or stays the same at high altitudes.
They are working together with the Federal Aviation Administration’s Civil Aerospace Medical Institute (CAMI) and are giving volunteers several color vision tests to identify relations between color blindness and different altitudes. The outcome of this study could provide new sources of information for the requirements on color vision when acquiring a pilots license.