Light can travel at different lengths, and different speeds/frequencies, which is often known as wavelengths. Wavelengths are the distance between two points, on the next wave. You when you see an object, or color, the image takes a step process to reach your brain, to interpret the object. Stage 1, is not seeing the object. Your eye is constructed of different parts, each with their own unique function. In the front of the eye, you have your iris, the colored part,the pupil, the cornea, and towards the inside, you have your aqueous humour. The aqueous humour is in the inside, that mosturizes that part of the eye. Towards the back, you then have your retina, optic nerve, and ligaments.
    The first step of seeing an object, is when it passes through the cornea, and is visible to the 

Rainbows are one of the joys of seeing the rain. Although we all love seeing the rainbow, we don't know how they are formed, or where the seven colors come from. The seven colors displayed in the rainbow, are the seven colors of the spectrum. Now that we know the seven colors, how are rainbows truly formed? When the rain is still fresh in the air and sky, the water droplets refract to form the colors of the spectrum. The water droplets break the seven colors down, so we can visually see the colors. In the sky, the rainbow only takes a portion of the sky, and that is because, on the electromagnetic spectrum chart, only the colors of the spectrum take a tiny portion of the chart itself.
    The colors seem to blend into one another, and that is because of the colors, and how they are ordered. So, technically, the rainbow is formed due to the internal reflection, and refraction coming from the light source. Reflecting, means it is simply coming back to your eyes, and refracting is the change in direction of the light. When the light is being refracted, thats how the rainbos contains it's arch shape.

Although, I have already theorized why te sky might be blue, I can now full explain it. The sky is blue, is similar to asking why the grass is green, or why the ocean is blue. Now, the ocean is blue due to color pigments, and several items in the ocean itself. The sky is blue, for a different reason. The sky is often thought of, as the light source in our sky, however, that is wrong. The sun is our light source, as when the night comes, it becomes darker. The light that is projected in the sky, are reflections, and the coloration cells in our eyes, that allow us to see the sky as blue. There are several colors, and shades of colors that we can view in the sky. Color blind people lack the part in the eye, where it allows them to see all colors.
    Back to the sky, if you were to take a mirror and shine light on it, depending on the type of surface the mirror is, is depicted on where the light goes. For example, if the mirror is laying on top of a bumpy rock, the light will appear as a different reflection go everywhere, and scatter. The scattering lights will disappear, if you have a smooth, flat surface. The sky is blue, according to scientists, due to the reflection of the light source. If you were to take a t.v. and center it in a dark room with chairs, you could see the chairs, simply because they are illuminated from the t.v. screen. They aren't exactly visible to the eye, but they are in the light source's reach.