So.
Why I decided to do this? I don't know.
I've gotten 4/10 of the Solar System characters done.

The Sun was lots of fun. I went with more of a bright palette, oranges, reds and yellows and the hair is long and flowy to represent the solar flares, etc.

Mercury I wanted to represent that quick rotation, so I added the wings in. Mercury doesn't have a whole lot of color though, so the color palette is mostly greyscale if not entirely.

Venus was also a lot of fun. The planet itself has a bit of a darker core/surface thus the skin but a lot of dusty clouds that swirl around, thus the cape.
And last that I've got done so far;

Earth was so much fun. I wanted to represent the fact that most of our planet is water, the dress kind of follows that flowing loose feel of water and the darkness of her skin/hair represents the deep rich soil that allows things to grow (the green on her).
I've still got;
Mars, Jupiter, Saturn, Uranus, Neptune and Pluto to do.
Why?
I... don't know.