Color plays a vital role in the world in which we live. Color can sway thinking, change actions, and cause reactions. Color, simply stated, is irreplaceable. In the human brain, the five sensory pathways are parallel to one another. However, in some situations, a cross-over from one pathway to the other occurs. One may see the color yellow and feel happy, black and feel sad, white and feel clean. Despite the amount of research done in the field and the widespread acceptance of many of its basic theories, chromology (the study of the psychology of color) is often doubted, seen by critics as a result of cultural conditioning affected by many aspects of the environment. Regardless, it is natural to place associations between colors and emotions. However, associations between colors and senses – sight, sound, smell, touch, or taste – is rare.

Synesthesia is a neurological condition that affects approximately five percent of the population, occurring most often in artists. This causes individuals to cross senses, wherein the stimulation of one sense leads to another cognitive reaction. Below are a few of the most common forms of this condition: