Rainbow Coloring Page for Kids: Free Printable PDF

Rainbows: Light, Water, and the Colors in the Sky

How a Rainbow Forms

A rainbow appears when sunlight interacts with water droplets suspended in the air. Each droplet acts like a tiny prism. Sunlight enters the front of the droplet and slows down as it moves from air into water, bending slightly in a process called refraction. The slowed light reflects off the inside back surface of the droplet, then bends again as it exits back into the air. Because different colors of light have different wavelengths, they bend by slightly different amounts — red bends the least and violet bends the most. This separation of wavelengths spreads white sunlight into its spectrum of colors, producing the arc we see in the sky.

The observer's position determines what they see. A rainbow is always centered on the point directly opposite the sun from the viewer's perspective, which is why the sun must be behind you and relatively low in the sky for a rainbow to appear. The arc has a radius of about 42 degrees from that anti-solar point for the red outer band and about 40 degrees for the violet inner band. Moving toward or away from the rainbow doesn't change its apparent distance — it always maintains the same angle from your position, which is why it appears to move with you.

The Seven Colors and ROY G BIV

Sir Isaac Newton was the first person to systematically describe the rainbow's color spectrum in the 1660s. Using a glass prism, he spread sunlight into its component colors and identified the bands he called red, orange, yellow, green, blue, indigo, and violet. Newton chose seven colors deliberately, partly because he believed in a correspondence between music and color — the rainbow's spectrum matched the seven notes of the musical scale in his theory. Modern color scientists note that indigo is actually a difficult distinction to make between blue and violet, and some contemporary science education uses a six-color model, but ROY G BIV remains the standard mnemonic taught to schoolchildren.

In nature, the boundaries between rainbow colors are not sharp lines. Each color blends gradually into the next across the arc, creating a smooth continuous spectrum rather than distinct stripes. The bold colored bands in coloring-book depictions, including this page's four-band design, represent a simplified version that makes the color sequence easy to practice. Coloring the four bands from outer to inner in red, orange, yellow, and green gives children a visual memory of the spectrum order without requiring every shade to be distinct.

Double Rainbows and Other Rare Variations

A double rainbow occurs when light reflects twice inside each water droplet before exiting. The second rainbow appears outside the first, with its colors in reverse order — violet on the outside and red on the inside. The sky between the two arcs, called Alexander's band, appears darker than the sky above or below because very little scattered light reaches that zone. Double rainbows are not rare on a bright rainy day, but the secondary arc is always fainter and requires attentive looking to spot clearly.

Fog bows are a white arc version of the rainbow produced by the much smaller water droplets in fog rather than rain. Because the droplets are so tiny, diffraction spreads the colors together and produces an arc that appears nearly white or faintly red on the outer edge and blue on the inner edge. Moonbows occur at night when moonlight rather than sunlight illuminates rain — they appear white to the naked eye because the light is too dim to trigger the color-sensitive cone cells in human vision, but a long-exposure photograph reveals full color. Fire bows and dew bows follow the same optics on different reflective surfaces.

Rainbows in Mythology and Culture

Cultures across the world have attached meaning to rainbows for thousands of years. In Norse mythology, the Bifrost is a burning rainbow bridge connecting the realm of the gods, Asgard, to the human world, Midgard. Norse texts describe it as trembling under the weight of Thor's chariot when he rides to and from Asgard. In ancient Greek mythology, Iris was the goddess of the rainbow and a messenger between the gods and humanity. The iris of the human eye is named after her because of the range of colors it can display.

In the Hebrew Bible, a rainbow appears after the flood as a covenant sign between God and Noah, promising that no flood would again cover the earth. This association with renewal and promise after storm has entered the everyday language of many cultures — a silver lining, a rainbow after the rain — as a phrase meaning that difficult times give way to better ones. The rainbow's visual appearance directly after heavy rain makes that metaphor natural and cross-cultural, appearing independently in Japanese, Inca, West African, and Aboriginal Australian traditions.

The Pot of Gold and Irish Folklore

The legend that a pot of gold lies at the end of a rainbow comes from Irish folklore. Leprechauns — small mischievous fairy shoemakers — are said to bury their treasure at rainbow endpoints. Since a rainbow has no physical endpoint that a person can walk to (it recedes as you approach it), the treasure is permanently out of reach, which gives the legend its bittersweet quality. The image of the rainbow's end as a place of hidden wealth entered broader English-language culture through the 19th and 20th centuries and became one of the most widely recognized symbols of an impossible or endlessly deferred goal.

Today the rainbow is also a symbol of diversity and inclusion across many international contexts, adopted by various movements in the 20th and 21st centuries as a visual representation of different groups existing together. Its natural origin as a spectrum of all visible light wavelengths, none more valid than another, lends the metaphor a scientific as well as a cultural resonance. A simple arc of color that forms for minutes after a rainstorm has accumulated an unusually large body of meaning across human history.