Confusion of Colours

What colour am I? Am I red, like the ruby in a ring? Or orange, burning bright, flickering from the fire? What colour am I? Am I yellow, sour as a lemon, piercing my tongue? Or green, envying the beauty of others around? What colour am I? Am I blue, sunken deep into the ocean? Or purple, reigning above all? I am not just one, and I need a REALLY good pun for you to understand what I am. For I am rare. I come with rain and shine. Maybe now you know my name. Because I am happiness and joy. I am hope and faith. I am all. I am rainbow. -Millie Cooper