In this app, you can change and select the TONE of color (version of Yellow) that you want, the TIME that you want the screen will be active and the BRIGHTNESS of your screen.
All the colors in Yellow Light are optimized to show a powerful radiant effect.
Psychology of Yellow Light
Yellow is the color of sunshine. It’s associated with joy, happiness, intellect, and energy.
Yellow produces a warming effect, arouses cheerfulness, stimulates mental activity, and generates muscle energy. Yellow is often associated with food. Bright, pure yellow is an attention getter, which is the reason taxicabs are painted this color. When overused, yellow may have a disturbing effect; it is known that babies cry more in yellow rooms. Yellow is seen before other colors when placed against black; this combination is often used to issue a warning. In heraldry, yellow indicates honor and loyalty. Later the meaning of yellow was connected with cowardice.
Use yellow to evoke pleasant, cheerful feelings. You can choose yellow to promote children’s products and items related to leisure. Yellow is very effective for attracting attention, so use it to highlight the most important elements of your design. Men usually perceive yellow as a very lighthearted, ‘childish’ color, so it is not recommended to use yellow when selling prestigious, expensive products to men – nobody will buy a yellow business suit or a yellow Mercedes. Yellow is an unstable and spontaneous color, so avoid using yellow if you want to suggest stability and safety. Light yellow tends to disappear into white, so it usually needs a dark color to highlight it. Shades of yellow are visually unappealing because they loose cheerfulness and become dingy.
Dull (dingy) yellow represents caution, decay, sickness, and jealousy.
Light yellow is associated with intellect, freshness, and joy.
Text extracted from http://www.color-wheel-pro.com/color-meaning.html