Final answer:
Blue is the color that promotes inner tranquility. Yellow color is seen when yellow light shines on a white paper or white light on a yellow paper, but not when yellow light shines on black paper or red and green lights shine on white paper.
Step-by-step explanation:
The color that is widely recognized for promoting inner tranquility is blue. Unlike red, which often signifies energy and intensity, blue has a calming influence and is associated with a peaceful mental state. This is in contrast to yellow, which typically denotes happiness and vitality, and green, which is often associated with nature and relaxation but to a lesser degree than blue in the context of inner peace.
When it comes to color perception, under normal lighting conditions, a student would observe a piece of paper as yellow if specific criteria are met. If yellow light shines on a white paper or if white light shines on a yellow paper, the student will see the paper as yellow. However, if yellow light shines on black paper, the student would not see the paper as yellow because the black paper absorbs all colors and reflects none. Additionally, when red and green lights shine on a white paper, this combination of light can be perceived as yellow because of the way our eyes process the mixing of colors.