You can paint the ceiling fan without taking it down, but there are a few things you need to do first. Ceiling fans are usually made of metal, so you'll need to use a primer designed for metal surfaces. When the primer dries, paint the fan with any color you like. Ensure that you are using the paint meant for use on metal surfaces. Also, use a foam brush instead of spray paint, as it will allow you to paint it without taking down all of the fan parts. You will only need to detach the blades.