Sunlight contains all the colors of the visible spectrum blended together into white light.

The longer version

The sun's outer layers glow because they are hot, and hot objects radiate across a broad, continuous range of wavelengths rather than a few isolated ones. By the time that mixture reaches the ground, it spans everything the eye can use, and the overlapping wavelengths sum to a whitish impression.

The spectrum is not flat, though: the sun peaks in the green part of the range, and the atmosphere trims the ultraviolet and parts of the infrared. Measured at the top of the atmosphere, the light is close to white but slightly cooler in tone. Candlelight is also broad, yet weighted far more toward red.

Where this entry sits

These facts explore how light behaves and how human eyes turn it into the colors we see. Along the way you meet rainbows, prisms, mirrors, shadows, lasers, and optical tricks that fool our vision every day. The full list sits on the Color and Light page, where every entry is listed in order.

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More From Color and Light

Eight more entries

Violet light has the shortest wavelength visible to humans, while red has the longest.

The sky looks blue because air molecules scatter short blue wavelengths more than long red ones.

Sunsets often look red because sunlight travels through more air, which scatters away the blue light.

Laser light differs from ordinary light because its waves are aligned and share a single wavelength.

The traditional spectrum is often listed as seven colors, including red, orange, yellow, green, blue, indigo, and violet.

Most people cannot distinguish indigo from blue or violet in an ordinary rainbow.

Color blindness most often involves difficulty telling red from green rather than seeing no color at all.

Some animals, including many birds, see ultraviolet light that human eyes cannot detect.

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