Response is regional. Attitudes are different in each region. This causes colors to have different responses from region to region. Response varies with climate. Compensation for temperature is possible with colors and may be necessary for the individual seasons of the year.
Response varies with light.
There is no color unless there is light. The quality and properties of the light cause each person to experience the same color differently when the light source varies. The usual deficiency is to red or green or both. Yellow vision may also follow digitalis or quinine poisoning. Red vision may follow retinal hemorrhage or snow blindness and from tobacco scotoma.