Why is the sky blue?

Do you know why the sky is blue? I think that the sky is blue because it absorbs all the colors except for the blue one and it reflects the blue one and the reflection goes back into your eyes. The colors that it absorbs are red, orange, yellow, green, blue, indigo, and violet.The way I remember that those are the colors is by a name, sort of like a boys name: Roy G. Biv. That is how I remember the colors. When the all of the other colors get absorbed into the sky, the blue one reflects it and comes back to meet your eyes.