Updated: Mar 8
"The Hue Heat Hypothesis (HHH) is based on the idea that light and colours of the environment can affect thermal perception and influence thermal comfort. Specifically, it states that, when spectral power distribution of light reaching an observer’s eye is characterized by long wavelengths in the visible spectrum, the space is perceived as warmer; conversely, when small wavelengths are predominant, the space is perceived as cooler."
-Bellia et al. (2019)
The hue heat hypothesis helps demonstrate how we consider certain qualities to be opposites even though we shouldn’t think of them as opposites based on experience, and how it can effect our behavior. Experiments show that people will hold a hot blue vessel longer than a hot red one and a cold red vessel longer than a cold blue one (Ziat et al. 2016). Blue coloration perceptually counteracts or moderates heat, and red counteracts coldness, making it clear that hot and blue are opposites in the mind, or psychothermal opposites, as predicted here based on semantic evidence. We know them to be opposites even though we wouldn’t learn this from normal experience. In normal experience it’s not even true in any absolute sense that blue and hot or red and cold are opposites. It’s only true in the mind and the substance of the brain.
It could be argued based on hue heat experiments that a bright hot object is more exciting than a hot dark or cold bright object, which themselves are more exciting than a cold dark one. The hot dark and cold bright objects, the ones we hold longer, at least in a simple, contact-time-based sense, are more likable or familiar than cold dark or hot bright ones. The results reflect sensory biases favoring hot—dark=0 and bright—cold=0 mixtures, with zero excitement balance, over hot—bright=2 and cold—dark=-2, with positive and negative balances. Adding blue to heat or heat to blue creates a perceptual mixture with a sort of complexity and moderation that red heat and blue coldness do not convey. It’s also been found that red light decreases cold pain thresholds and increases the perceived loudness of louder sounds, or increases sensitivity to higher temperature and sound volume (Landgrebe et al. 2008), and that people feel warmer observing orange than blue (Matsubara 2004, Chinazzo et al. 2017) and in yellow light than blue light (Albers et al. 2015): "Subjects tend to have slightly warmer thermal sensations in yellow light and slightly colder sensations in blue light."
These studies show that we associate the colors red, orange and yellow with each other in a category which is at least in a thermal sense opposite to the color blue. A simple potential explanation for the hue heat effect is that red and yellow light heat the brain and/or visual sensory system slightly more than blue light. Assuming that this heat corresponds to some extent with psychological excitement in animals could possibly help explain the widespread use of red, yellow and orange coloration in animals for aposematic purposes as well as their use in sexual signals and association with sex organs. It should be noted that some hue heat experiments have failed to find a significant effect (e.g., Bennett et al. 1972).
Albers, Frank, Julia Maier, and Claudia Marggraf-Micheel. "In search of evidence for the hue-heat hypothesis in the aircraft cabin." Lighting Research & Technology 47.4 (2015): 483-494.
Bellia, Laura, et al. "Dynamic Simulation of a Lighting System Based on the Hue-Heat Hypothesis." Proceedings of the 16th IBPSA Conference (2019): 2434-2441.
Bennett, Corwin A., and Paule Rey. "What's so hot about red?." Human Factors 14.2 (1972): 149-154.
Chinazzo, Giorgia, et al. The effect of short exposure to coloured light on thermal perception: A study using Virtual Reality. No. CONF. 2017.
Landgrebe, Michael et al. “Effects of colour exposure on auditory and somatosensory perception--hints for cross-modal plasticity.” Neuro endocrinology letters vol. 29,4 (2008): 518-21. https://www.nel.edu/userfiles/articlesnew/NEL290408A12.pdf.
Matsubara, Naoki, Akira Gassho, and Yoshihito Kurazumi. "Facilitatory effects of environmental sounds on hue-heat phenomena." 18th Int. Congr. Acoust. Vol. 2. 2004.
Ziat, Mounia, et al. “A Century Later, the Hue-Heat Hypothesis: Does Color Truly Affect Temperature Perception?” Haptics: Perception, Devices, Control, and Applications Lecture Notes in Computer Science, 2016, pp. 273–280., doi:10.1007/978-3-319-42321-0_25.