Violet is the rarest color in nature because it is the most energetically demanding visible light for pigments to reflect and for nanostructures to scatter.

Creating a perfect red pigment that is vivid, durable, and nontoxic is likely impossible.

The same pigments that enable photosynthesis—chlorophyll a and b—are also responsible for giving most plants their green color.

Starting with red, colorful objects will appear to lose their colors the deeper they are submerged because water scatters light, reducing the amount available to reflect off objects and be observed.

Humans can distinguish about 10 million colors—a number that is limited by photopigments that only activate when exposed to specific wavelengths of light.

Not all colored materials can become pigments—the process of grinding materials down into smaller particles may destroy the color-producing molecules.

View a gallery of plants made to shine using ultraviolet-induced visible fluorescence photography, in which organisms re-emit the ultraviolet light they are exposed to in vibrant, glowing colors.

When processing light, the brain can perceive colors with no natural wavelength

Virtually all plants are biofluorescent because their photosynthesis is powered by chlorophyll, a pigment that glows red as a way to get rid of excess energy when exposed to ultraviolet light.

The chlorophyll in plants captures energy in the form of red and blue light

Blood can be blue, green, magenta, or transparent due to differences in the oxygen-carrying respiratory pigments they contain.

View a gallery of biofluorescent animals, which contain cells that emit various colors when exposed to ultraviolet light.

Egg yolks and carrots have the same pigments that contribute to the yellow and orange colors of fall foliage.

The color blue is almost never mentioned in ancient Greek literature

High solar activity can produce pink and purple auroras

View an animation of how certain chemicals fluoresce—that is, emit visible light after having absorbed higher-energy light, such as ultraviolet radiation.

Some organisms can change color by quickly revealing or hiding various pigments, as seen in octopuses, squids, and other cephalopods.

Fossilized pigment granules have enabled scientists to deduce the colors of long-extinct organisms, including dinosaurs.

The colors of auroras change with the intensity of solar activity and with altitude because of differences in atmospheric density and chemical composition.

Tetrachromacy allows humans to observe 10 times the normal amount of colors

Breaking down sunlight and why the sun appears yellow despite emitting green light the most

By separating light with tools such as prisms, scientists can reveal the presence and composition of celestial matter by identifying color fingerprints unique to specific elements and molecules.

Evolution doesn't want you to see these animals

Biofluorescent animals—those that absorb light, such as ultraviolet rays, and re-emit other types of light, such as neon green—include some flying squirrels, scorpions, sea turtles, and platypuses.

Photographer captures glowing flowers in ultraviolet light

Sunsets can exhibit a greater variety of colors due to a greater range of cloud heights and atmospheric composition.

Bioluminescence became common in the ocean to support survival in dark environments

Blood color differs across the animal kingdom, with some animals producing blood that appears green (a group of lizards in New Guinea) or blue (horseshoe crabs).

Water is naturally tinted with a slight blue, but sediments and organics can alter its color

Leaves have orange and yellow pigments year-round, but they are masked until the fall, when shorter days reduce the production of chlorophyll, a green pigment.

Gold has a yellowish appearance rather than the silvery color of most metals because of special relativity, which causes gold's electrons to absorb blue light.

Blacklights can illuminate certain biological materials, including blood, teeth, and fingernails, because they contain fluorophores—molecules that visibly glow immediately after exposure to higher-energy light.

Incinerated skeletons, animal blood, and fermented animal waste were among the ingredients used to make the pigments in some of art history's most famous paintings.

Rayleigh scattering of light gives the atmosphere its blue skies and red sunsets

Instead of consuming water and carbon dioxide to produce oxygen and sugar, anoxygenic photosynthesis involves alternative reactants and products.

Colored diamonds result from elemental impurities, structural deformities, and exposure to radiation.

The RGB color system resembles how quantum chromodynamics models quarks and the strong nuclear force—both quarks and gluons carry color charge.

Synchrotron radiation has revealed the fur color of creatures millions of years old

Because it is observed in organisms that are not closely related, biofluorescence is thought to have emerged independently many times in nature—over 100 in fish alone.

The 2008 Nobel Prize in chemistry was awarded for discovering and developing uses for green fluorescent protein—a biomolecule found in some Pacific Northwest jellyfish.

Atmospheric composition and temperature impact the color of lightning

The outermost shell of electrons in an atom dictates how it bonds to other atoms, including those of the same element, and the properties of the materials composed of those atoms.

Scientists create contact lenses that give you infrared vision

Some corals absorb harmful ultraviolet radiation and re-emit it as visible light, thereby protecting symbiotic algae within their tissues and providing them with energy for photosynthesis.

Chameleons change color by altering the spacing of nanocrystals under their skin, which changes what colors of light are absorbed and reflected.

Colorizers convert Hubble's gray scale images into color composites of different wavelengths

Color originates from the brain processing light of varying wavelengths

The weakest form of light that is dangerous to humans is ultraviolet

The different energy levels of each element result in unique colors when burned

Wood that changed the color of water was the earliest recorded example of fluorescence

Satellites can be used to measure photosynthetic activity worldwide by observing the red, biofluorescent light emitted by chlorophyll in plants.