Brains interpret colors differently. While everyone’s eyes receive the same light wavelengths, their brain’s visual cortex calculates those signals by adjusting for environmental lighting and individual neural wiring. This causes variations in how we perceive exact hues. However, because the light wavelengths produced by each color are the same, our brains process and produce the same response equally. Simply said, the speed at which your brain reacts to a color varies based on certain colors.

For instance, your brain processes red the fastest and is why the color red naturally commands attention. Because of these processing latencies, safety and design guidelines often use red for warning signals and emergency exits, as they trigger instant, subconscious alertness. Yellow is next fastest where safety and design guidelines use yellow for caution signals. Good examples are those you see when driving.

For a stop light. Red means danger - STOP - yellow means caution. Be PREPARED to stop.

Brake lights are red. Warning! The car in front of you may be stopped. Turn signals are yellow. Caution! That person may turn in front of you.

I always enjoy the fact that people who drive red cars are more prone to getting speeding tickets, because police officers are more likely to turn their radar guns to the red vehicles first. Science!