Color is an emotional phenomenon. Each experience with color starts with a physiologic reaction to the light. The eye is the organ that perceives light. When light enters the pupil of the eye, it is reflected on the retina at the back of the eye. The retina is a complex structure, consisting of varied layers of interconnected nerve cells. Only photo-receptor cells are light sensitive. These are classified into two types: rods and cones. While rods mainly provide white/black vision at low levels of light, cones ensure daylight vision and perception of colors.
Colors were not studied deeply as a field until the 18th century. The concept achieved widespread recognition both philosophically and scientifically as a result of the experiments conducted by Isaac Newton. In this period, people writing about and studying colors were not artists. New studies on color are generally based on the observations made and studies conducted by Isaac Newton and Johann von Wolfgang Goethe. The opinion of Newton that color is singularly produced by light is considered to be the basis that modern physics relies on.
Color is produced by sunlight. The fact that colors appear brighter and livelier on sunny days but look darker and duller in overcast weather demonstrates how colors depend on light. Everything loses shape and color in the dark, in the absence of light. Various wavelengths of light shine on the surface of an object to be either absorbed or diminished except the color reflected by the object. This color is extracted from the retinal wall cells of the eye and reflected. For example, an object appears to be blue because it only reflects blue light and absorbs other colors in the sunlight. Objects in nature appear lighter or darker in color based on the amount of light they absorb or reflect. Colors that are visible to the eye are explained on the basis of cones. The human eye has 3 different types of cones and these are red, green and blue. These three wavelengths reveal millions of colors. Detector nerve cells absorb various tones and send a message to the brain to resolve the colors. In other words, the eyes see the colors but they are perceived by the brain and subconscious. The brain stimuli is also transmitted to the main glands that regulate endocrine, causing emotional and psychological reactions. (Nielsen & Taylor, 2007)
Colors could be the visual expression of an emotion or mood. Many colors have physiologic effects on the body, and as such could be used to stimulate or calm. Colors could alert or stimulate the body. The way we react to a flashing red light is not the same as the way we react to a flashing green light. This happens subconsciously.