That's because, even though those colors exist, you've probably never seen them. Red-green and yellow-blue are the so-called "forbidden colors." Composed of pairs of hues whose light frequencies automatically cancel each other out in the human eye, they're supposed to be impossible to see simultaneously.
Red and orange seem to be the clear winner when it comes to eye-catching colors. These colors tend to stand out and are therefore used on many warning signs or safety equipment. Yellow is another color that comes in a close second to red and orange in popularity.
Bright, bold and vibrant colors work best. However, any color that contrasts with your background will serve you well. Shades of yellow, orange, red, green, purple and blue are all excellent color choices to grab a user's attention.
As for the least preferred colors, yellow is mentioned in eight studies, while orange and green-yellow are mentioned in five studies each. Thus, the most attractive color is blue, the second most preferred is red, followed by green, while yellow was found to be the least preferred color (Figure 1).
Yellow is the least favorite color, preferred by only five percent of people.
Gold. According to Feng Shui principles, the colour gold can help manifest good luck and it also plays an important role in attracting money.
Yellow is widely recognized as the happiest color in the world and comes with a scientific pedigree to back up this esteemed honor. Research has suggested two main reasons why yellow is considered the happiest color.
Happy colors are bright, warm colors like yellow, orange, pink and red.
The three additive primary colours are red, green, and blue; this means that, by additively mixing the colours red, green, and blue in varying amounts, almost all other colours can be produced, and, when the three primaries are added together in equal amounts, white is produced.
White does amazing things for all colors. It multiplies the intensity of any shade and makes it stand out that much more.
Green is the color of ingenuity and learning. "Geniuses pick green," said Robert DeNiro in Meet The Parents. Scientists have found that a room painted green can actually improve a child's learning speed and retention.
'Cool greys are best paired with cooler colour schemes, such as blue, green, and light purple, while warm greys better complement reds, oranges, and yellows. For fans of the monochrome look, incorporate different shades of grey, alongside white and black, to create depth and visual interest.
Opponent process theory suggests that the most contrasting color pairs are red–green and blue–yellow.
Red and green cancel each other as do yellow and blue. They further reasoned that if one started with a color such as bluish green it should be possible to mix this color with a unique yellow to cancel out the blue content leaving only green. This is the basic idea behind the hue cancellation technique.
Yellow is said to be the happiest color, promoting optimism and positive thinking.
Lucky colours: Green (especially light green), silver, creamy yellow and grey are good.
Green – Quiet and restful, green is a soothing color that can invite harmony and diffuse anxiety. Blue – A highly peaceful color, blue can be especially helpful for stress management because it can encourage a powerful sense of calm. Purple – In many cultures, shades of violet represent strength, wisdom and peace.