 Viewing color has been widely shown to change an individual's emotional state and stimulate neurons.The Lüscher color test observes from experiments that when individuals are required to contemplate pure red for varying lengths of time, [the experiments] have shown that this color decidedly has a stimulating effect on the nervous system; blood pressure increases, and respiration rate and heart rate both increase.Pure blue, on the other hand, has the reverse effect; observers experience a decline in blood pressure, heart rate, and breathing.