The naked eye can only see light that has a path within the visible spectrum. A spectrum is a rainbow of colors arranged in order from darkest to lightest. The visible spectrum is made up of red, orange, yellow, green, blue, indigo, and purple. When these colors blend together, they trick the eyes into thinking that the combination is white. White light is made up of all the colors in the spectrum.
Red light gives off the brightest beam of light because it has the longest wavelength.
Purple light, also called violet light, has the shortest wavelength. Sunlight has all the colors, so it is white. Now that we know a little about light, let's apply our knowledge to the sky. The sky is a large ocean of air that actually has no color at all. The sky has a whole bunch of particles floating in it, such as dust, smoke, and ash.