A rainbow is a multicolored arc, or curved line, in the sky that can be seen when the sun shines through falling rain. The pattern of colors starts with red on the outside and changes through orange, yellow, green, blue, indigo, and violet on the inside. Most rainbows form when the suns rays strike raindrops falling from faraway rain clouds. The separated light waves appear as the colors of a rainbow. The brightest and most common type of rainbow is called a primary bow, and sometimes a fainter rainbow forms outside the primary bow, which is called a secondary bow or a double rainbow. A secondary bow forms when the light bends twice inside the water drops. The first bend makes the primary bow, and the second bend makes the secondary bow. The colors in the secondary bow appear in the opposite order of the colors in the primary bow.

Rainbows can be seen in mist, fog, during or after it rains, and even in dew. They always show up on the opposite side the sun is shining. Rainbows are created when white light is bent (refracted) while entering a droplet of water, split into separate colors, and reflected back. A rainbow is actually round like a circle, and on the ground, the bottom part is hidden, but in the sky, like from a flying airplane, it can be seen as a circle around the point opposite the sun. Rainbows often appear after storms and are popular symbols for peace in many cultures.

Here are some fun facts about rainbows for kids:

• Rainbows are multi-colored arcs that form in the sky and are formed when sunlight shines through the water. As a result, light reflects off the water droplets, bends (called refraction) and splits.
• When sunlight shines through the water droplets, it splits into seven colors. The seven colors of the rainbow are red, orange, yellow, green, blue, indigo, and violet.
• The rainbow effect can be seen when there are water drops in the air, and the sun is giving light at the back of the observer at a low distance up or angle.
• Rainbows always appear opposite the sun: they form circles around the shadow of your head (which is the point opposite the sun).
• The rainbow has no definite number of physical colors, but seven are traditionally listed. Computer screens cannot show them precisely but can approximate them:
  • Red (web color) (Hex: #FF0000) (RGB: 255, 0, 0)
  • Orange (color wheel Orange) (Hex: #FF7F00) (RGB: 255, 127, 0)
  • Yellow (web color) (Hex: #FFFF00) (RGB: 255, 255, 0)
  • Green (X11) (Electric Green) (HTML/CSS “Lime”) (Color wheel green) (Hex: #00FF00) (RGB: 0, 255, 0)
  • Blue (web color) (Hex: #0000FF) (RGB: 0, 0, 255)
  • Indigo (web color) (Hex: #4B0082) (RGB: 75, 0, 130)
  • Violet (web color) (Hex: #8B00FF) (RGB: 139, 0, 255)