Colors seen with our eyes have its effect on our feelings, and our souls. The unique color of gold has a special physiological effect which gave birth to the very term “golden”.
Colors, the visual perception we see with our eyes, are the reaction between the spectrum light and the eye. The eyes distinguish the wavelengths or frequencies of light reflected on an object and the brain “translate” these signals into visual colors.
The color of gold is a little different story than colors of others metals. Other pure metals tend to be silvery white, gray or reddish orange, while pure gold is bright yellow.
This golden color is due to the free electrons in the outermost energy level of the gold atom moves as a collective medium called “plasmon”. The frequency of those electrons usually lies in the ultraviolet region that the human eye can’t see, and the brain translates them into white. While in the case of gold, these electrons lie in the visible range and the brain translate these frequency as bright yellow.
As for the general idea concerning the color of gold alloys, the higher copper percentage in the gold alloy, the more reddish it becomes. While white metals such as silver and other metals give gold a more whitish color and luster. These are most common colors of gold in jewelry shops.
Rose or pink gold is a gold alloy with higher percentage of copper, ranging from 25% to 50% copper. While the popular red gold in the Middle East is gold alloy with more than 40% copper.
White gold is an alloy of white metal such as nickel, magnesium or palladium with 10% white metal and 90% gold. Silver, although it’s a white metal, gives a green gold color. Gold in the green-gold alloy ranges from 73% to 75% of the alloy.
Recently, a femtosecond laser pulse applied to the surface of gold deforms the surface of this metal on the Nano-level, giving it black color. This literary “black gold” is regular gold whose deformed surface can absorb any visible light, making it deep black. Other methods of making black gold involve electroplating with black rhodium or ruthenium, controlled oxidation and patination (rusting and tarnishing).
As for the psychological effect of pure gold color on man, it provokes different powerful emotions at the same time. The yellow wavelength is relatively long, making it the strongest physiological color. It gives birth to optimism and depression, fear and confidence, creativity and irrationality, friendliness and fragility at the same time in our hearts!
The golden yellow color, which is commonly reddish as well, has additional physical properties as well it emotional effect on human physiology. It provides us with feelings of energy, courage and aggression. It raises our pulse calmly and slowly, yet powerfully.
Gold color is the perfect combination between red, yellow and white. No wonder our ancestors and ancient civilizations relate it to the sun and the gods. Gold is truly a powerful element; its color is just another plus to its physical properties.