Color theorists suspect that many color associations emerge from evolutionary ingrained responses to color stimuli (Mollon, 1989 http://jeb.biologists.org/content/146/1/21.full.pdf). Research indicates that colors often serve a signal function for nonhuman animals (e.g., the redness of fruit signals readiness for eating), thereby facilitating fitness-relevant behavior (Hutchings, J. (1997). Color in plants, animals, and man. In K. Nassau
(Ed.), Color for Science, Art, and Technology (pp. 222–246). Amsterdam:
Elsevier). Of the existing research that is theoretically based, most has been loosely guided by Goldstein’s 1942 (http://psycnet.apa.org/index.cfm?fa=search.displayRecord&UID=1942-04745-001) proposal that red and yellow are naturally experienced as stimulating and disagreeable, that these colors focus people on the outward environment, and that they produce forceful, expansive behavior, whereas green and blue are experienced as quieting and agreeable, focus people inward, and produce reserved, stable behavior. Subsequent researchers have tended to interpret Goldstein’s proposal in terms of wavelength and arousal: Longer-wavelength colors like red/orange are experienced as arousing, and shorter-wavelength colors like green/blue are experienced as calming.
Experiments demonstrated that the perception of red prior to an achievement
task impairs performance relative to the perception of green or an achromatic color. This effect was documented in two different countries (the United States and Germany), with two different age groups (high school and undergraduate), in two different experimental settings (laboratory and classroom), using two different types of color presentation (participant number and test cover), using four different variants of red and green hues, using all three achromatic colors (black, white, and gray), and using both language-based and number-based achievement tasks. Evidence from funnel debriefing data, self-report process data, and perceived competence data supports premise that this undermining
effect of red takes place outside of individuals’ conscious awareness. These experiments also demonstrated that the perception of red prior to an achievement task, relative to the perception of green or an achromatic color, indeed evokes avoidance motivation, as indicated by participants’ choice of easy relative to difficult tasks. The present findings represent the first demonstration of a
direct, replicable effect of color on performance using rigorous experimental methods. This research was explicitly designed to address weaknesses, and (a) use of tightly controlled color presentations, (b) use of colors perceived to
be typical and matched on saturation and brightness, and (c) adherence to basic methodological considerations (such as keeping the experimenter blind to the hypotheses and color conditions) allowed to clearly and emphatically document a relation between a relation between red and performance (http://www.psych.rochester.edu/people/elliot_andrew/assets/pdf/2007_ElliotMaierMollerFriedmanMeinhardt_Color.pdf)
Color discrimination is the measurement of how well an observer can
differentiate between colors. It is understood that human color vision demonstrates variability both within an individual observer (inter-observer) and from observer to observer (intra-observer) (http://www.ncbi.nlm.nih.gov/pubmed/15811001).
These variabilities demonstrated by the human visual system can be broken down into two primary categories, color vision deficiency and normal color vision. The tests developed to quantify the ability of color discrimination include the Colorcurve HVC Color Vision Skill test and the Farnsworth Munsell 100 Hue test. Research using these tests indicate that large variances of the colors red and yellow are noticed (more than normal variance given by the test guidelines). However, per the paper more experiment data is needed to confirm these
findings. (http://www.cis.rit.edu/research/mcsl2/research/PDFs/ColorCurve.pdf).
Results from another study titled Differential binding of colors to objects in memory: red and yellow stick better than blue and green
indicate that feature binding in memory is not a uniform process by which any attended feature is automatically bound into unitary memory representations. Rather, memory binding seems to vary across different subtypes of features, a finding that supports recent research showing that object features are stored in memory rather independently from each other (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4347302/).