The only night-light sources available to early humans were open fires, torches and eventually oil lamps…all of which are light close to the red range. Perhaps the answer is the “Grandfather” clause: That’s the way it’s always been so it must be right – or – a memorable candle-lit dinner with your sweetheart???
Scientifically, the color of light is measured in Kelvin. Candle light is approximately 1500 Kelvin, incandescent bulbs are 2500K and fluorescent can range from 2800K to 6500K. In the 1950’s, commercial fluorescents were pink or “Warm White” and more recently the CFL market has introduced warmer colors. LEDs can range from 2600K to 8300K and can be designed to adjust the incoming electricity to change colors.
Poultry producers are realizing the benefits of different colors and intensities of light at various stages of the bird’s development to promote early growth and increase egg production. Perhaps the bird feels the candle-lit dinner emotion.