If you wander outside on a misty morning you may come across a white rainbow - called a fogbow! White rainbows need three things to form: mist, the sun, and you. White rainbows are the same as regular rainbows, except they only form when the water drops in the air are super small. To find a white rainbow, go out when the Sun is low in the sky, like in the morning or evening. You want the Sun to be behind you so that a ~40 degree angle from the droplet to you and the sun is achievable. You'll need to be in a very thin fog, thin enough that the sun shines through but thick enough to reflect the sun's light back. Look away from the sun (the same way you do with a regular rainbow).