Please help, I don't know what to do. 

To change the color of the sky, type /os env sky [hex color].

To change the color of the clouds, type /os env clouds [hex color].

Just be aware that the sky color will blend in with the fog color at the horizon. You can also type /help os env for more information about the environment settings on your OS map. You can also directly PM me if you still need help with something 🙂