Blue lighting calms us faster than conventional white light after short-term stress, researchers of the Brain-computer Interface Lab at the University of Granada, Spain, reported.

Previous studies on the effects of light on human physiology or changes in emotions have experimented with different colours. For example, different hues were linked to different pleasure and arousal levels.

A study of the effects of colours on the learning environment showed that pale colours relaxed more than vivid colours. Heart rates were found to decrease with short-wave colours such as blue, green, and violet. Another study found that pink light was useful in reducing aggression in prison.

Short-term stress is a common everyday life occurrence, especially in social or interpersonal relationships such as argument with a friend, or being pressured to finish a task. In this new study, researchers therefore aimed to assess the effect of blue lighting after short-term stress.

They stressed twelve study participants, and then let them relax in a room with either blue or white lighting. Participants were monitored for their physiological signs throughout the experiment using electrocardiographic (ECG) and electroencephalographic (EEG).

Results show that blue lighting relaxes faster than conventional white lighting after short-term stress. The time to relaxation was reduced by approximately three-fold, from 3.5 to 1.1 minutes. But a convergence time of 3.5 to 5 minutes was also observed, after which the advantage of blue lighting disappeared.