The Department of Transportation contacts you and asks what colour they should make their road signs so that they will be most visible at night. Given what you have learned in this class about the sensitivity of rods under conditions of low illumination, one colour that you would NOT want to pick is
A)yellow
B)blue
C)green
D)red

Question

Quizplus · Accepted Answer

Rods, which are more active under low light conditions, are less sensitive to longer wavelengths like those of red light. Therefore, red signs would be less visible at night compared to signs of other colors.

The Department of Transportation Contacts You and Asks What Colour