Color

The small portion of the electromagnetic spectrum that makes up visible light contains all the color that our eyes can detect. Using color for symbols is one of the most basic usage of symbols we learn early in our development. For example, we understand RED as a universal "hot", "stop" or "danger" symbol. Colors can set a desired mood. Seeing blue dyed water in a toilet gives us a sense of cleanliness and puts us at ease. Complimentary colors can be paired up in an advertisement to attract our eye to it; colors are grouped together in many other ways similar to this for a multitude of desired effects as well. People devote their entire lives to understanding how humans interpret color and how color can be used to manipulate our thought processes.