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

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

Paints are primarily made of pigments from rocks, plants, insects, or synthetic sources, combined with binding agents, solvents, and other potential additives for specific purposes.

Studies of tattoo inks have identified over 100 pigments, which have historically included toxic metals but now include organic compounds.

Cow urine, cuttlefish ink, and burned white lead were among the substances used as pigments throughout history.

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.

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

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

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.

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

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

From dragon's blood to bone black, explore a timeline of pigments used throughout history, including each pigment's composition, preparation methods, and uses.

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.

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.

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

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

Color originates from the brain processing light of varying wavelengths

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

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

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.

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

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

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.

Light appears to slow down as it travels through different materials

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.

Flamingos get their pink color from pigments in their food, but they cannot be any color because their bodies cannot process every type of pigment.

Some octopuses change color while they sleep, potentially in response to dreaming about hiding, hunting, or other activities that involve changing color while awake.

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

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

While black tattoo removal can be done with a single laser, removing multicolored tattoos may require multiple lasers due to the variety of pigments.

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

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

Lasers are classified based on their gain medium and mode of emission

Explore the chemical compounds found in fireworks

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.

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.

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

Chromium contaminants in a ruby crystal gave the world's first laser its red color

Humans experience the world subjectively. What does that mean for scientific research?

LEDs emit pure colors, while incandescent bulbs filter white light

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.

Objects can be made invisible through refraction, in which light from behind an object is bent around it, making only the background visible.

Scientists can tag distinct proteins with fluorescent probes that emit different colors, allowing them to visualize multiple biochemical processes simultaneously.

Atmospheric composition and temperature impact the color of lightning

How scientists determine elemental composition based on the light emitted by cooling atoms

High solar activity can produce pink and purple auroras

Light appears to slow as it travels through transparent materials due to interactions with the charged particles in the atoms of the material.

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