You're using EGA colours? okay:
this map is four different ways of displaying the same 64 colours.
sorted roughly for hue, luminance and saturation.
this is pretty similar to the previous one, just a sort of skeletal display of the same data, to show the most obvious ramps.
these are colour cube slices, which are harder to explain... basically it's a map of how much red, green and blue makes up each colour. the second one is more or less a flipped and rotated version of the same cube, to show some different ramps.
I've picked out the sky colours you're using, in white. You can see how - using each map, you could find a slightly greener shade for these colours, right?