Long ago, numerous ancient cultures, like the Egyptians and Chinese practiced chromotherapy, the use of colors to heal. According to psychology.about.com, chromotherapy can be called light therapy or colourology and is still used to this day for certain treatments.

The color yellow can be described as either cheerful and warm or anxious and disconcerting. Most people tend to lose their tempers in yellow rooms, and babies tend to cry more in a yellow room which is why it is best to paint a nursery in a neutral color.

Due to all the light that is reflected off of yellow it can be the most fatiguing out of the colors. If it is used on the computer or TV most people will feel fatigue in their eyes due to eyestrain. According to colour-affects.co.uk yellow is so bright it is used in small amounts for road signs because it will catch someone’s eye rather than a blue or a green that fades away.

If it is used the right away many people can feel feelings of optimism and high self-esteem. But if it used too much or in the wrong way people can become depressed, have fear and anxiety. The yellow wavelength is longer and stimulating so therefore, the color yellow is the strongest color, psychologically.
According to empower-yourself-with-color-psychology.com a dark shade of yellow represents depression or melancholy. A golden yellow represents a loner with intense curiosity and interest in digging up facts. Light yellow represents a clear mind and lets it be open and alert.