> Aunt Sev, why is the sky blue?
< Hm. What colour do you think it should be?
> *giggles* Purple!
< But it is purple sometimes. When was the last time you saw a purple sky?
>
last night's sunset!
< That's right. Now why would colours change when the sun changes angle? Is there somewhere else you can see purple in the sky?
> I dunno where?
< Oh, you know. You love these, you see them after the rain.
> RAINBOWS!
< And how do the colours spread out on the rainbow?
> red, orange, yellow, green, blue, indigo, violet!
< That's right! Notice that blue is right there next to the purples? I wonder if that has something to do with it.

