なぜ黄色信号が必要なのか？黄色対白色
First of all, the color temperature actually effects visibility and safety and not just a cosmetic choice up to personal taste or favourite.
Color temperature is a way to describe the light appearance.The true white light also known as neutral white, falls right around 5K Kelvin on scale. The light starts to turn blue when the scale goes up, sharper and brighter. However the blue fatigue would occur. That’s why there’s less eye strain with less blue light.
White light is sharp and will reach far. When there comes the fog and snow, each little substance could reflect and blind us.Our eyes react less stress to amber light at around 3K Kelvin color temperature. And we can focus on terrain even in low visibility situations with the yellow light.
