There are a few posts/guides on here about how to change the skybox (specifically DK's) so search around for that if you don't understand it.
I decided to take a majority of the values used in col-8 for the outlands and see that they come up as when applied in eastern kingdoms. This is mostly just for reference.
9 - Complete black, can't see anything but what has a glow.
380 - Saturated blue sky ,with green fog.
383 - Saturated dark blue sky.
385 - Purple sky.
441 - Dull green sky.
489 - Dark navy blue sky.
491 - Purple sky, with yellow/white clouds.
505 - Saturated yellowish/black/tan sky, with maroon overlay.
506 - Blue/green sky, with purplish lighting.
518 - Black to grey sky, with bright green fog/lighting.
553 - Netherstorm.
At the moment I'm working on the rest of the col-8 values and I'll add to this guide as I finish.