A good friend of mine, who's a doctor, is very well travelled, and he told me he's seen skies of different worlds take all the colors of the rainbow (and the grayscale to boot). I suspect that he might be pulling my leg, since he does tend to exaggerate on occasion.

![The refreshing green sky of home][1]
The welcome green glare of the homeworld's sky

So, is my friend lying or can the sky really be of any color (besides octarine)?

If the whole spectrum is too hard, I'm specifically (and in this order) interested in:

• Green
• Gray
• Purple
• Orange
• Vermillion (I don't actually know what color that is, I just like the name)

To clarify: I don't mean briefly for a minute, I want it that color a significant portion of the day. And no, it need not be Earth, and the system star can be whatever is best for your color-purposes. And no, you don't need to address all the colors, (I mostly care about green) but extra brownie points if you do. [1]: https://i.sstatic.net/DEwmB.jpg