Fundamental Study of Physiological Evaluation by Paired Comparison Test and Heart Rate Variability: The Effect of Chromatic Lights on Living Organisms

SUMMARY The popularization of LEDs and the development of light control technology have provided chromatic lights such as red, blue, and green. Chromatic lights are attracting attention in connection with the psychology and physiological effects of color. It is predicted that chromatic lights will result in favorable innovations in life spaces. This investigation studied chromatic lights as related to heart rate variability (HRV), using a psychological methodology, that is, the paired comparison test. The subjects of the paired comparison test were 14 healthy participants (age 21.9 ±3.7 years). The HRV subjects were seven healthy participants (age 24.0 ± 3.9 years). We examined the experimental results from two viewpoints. (1) In the results of the paired comparison test, the scores for white‐ice, yellow, and green were higher than those for the other colors, and the scores for blue, red, and pink were lower than those for the other colors. (2) In the results for HRV, the mean high‐frequency (HF) values for white‐ice, yellow, and green were higher than those for the other colors, and the mean HF values for blue, red, and pink were lower than those for the other colors. It is concluded that by using physiological parameters and a questionnaire it is possible to analyze the effect of chromatic lights on living organisms.