That's funny. I made that spectral clouds scene and it was never an animation. I guess it got saved that way by mistake.

As far as the green, the color wheel in C7 works.  So, you should be able to get the sky to stay whatever color you like.

Also, that is a very informative tute for the RSE.

I'll also be posting  a new landscape, maybe later today, that will appear in ImagineFX magazine  with their Carrara 7Pro review.