The Basics of Vision

Light enters the eye and hits the retina. At the back of the retina we have a concentrated pit of rods and cones:
Eye Illustration

The signals are sent to the brain by the cones, which have a sensitivity to a certain color: red, green, or blue. Cones sensitive to red are most abundant in the center of the retina, and cones sensitive to green and blue become more prevalent closer to the edge. This is the reason our eyes are most sensitive to red.

To represent danger or to capture the player’s attention, red is a great choice of color. Our own biology tells us clearly how to optimally distribute color in our designs:
Focus and Periphery area

Critical and Secondary information

This information is particularly important in HUD design. To keep the players in the game, we want to put the most important information in the center and secondary information on the periphery.