A rainbow is a curved band of colors in the sky. People say it has six or seven colors.

The colors come in the same order each time. Red is on the outside. Blue and violet are inside.

You can say them this way. Red, orange, yellow, green, blue, indigo, violet.

Sunlight looks white. But it is made of all the colors mixed together.

A prism is a piece of glass. It splits a beam of sunlight into rainbow colors.

A rainbow needs sunshine and water drops in the air. Rain is one kind of water drops.

Where you stand matters. The sun must be behind you. The water drops are in front of you.

A rainbow shows up opposite the sun. You must look away from the sun to see one.

Rainbows often show up after a rain shower, when the sun comes out.

You can see one in the spray from a hose, a sprinkler or a waterfall.

Here is a surprise. A rainbow is really a full circle. The ground hides the lower part, so we see an arc.

Sometimes two rainbows show at once. A bright one, and a fainter one above it with its colors flipped.

Words to know

• prism: color-splitting glass
• arc: curved line
• opposite: across from