micoach is all you need to get the results you want.
I'm a 10-12 and bought the medium but probably should have bought the small as these are slghtly loose. They're a good length in that they're not too short unlike some of the tennis dresses and other tennis skorts I have seen which are fine when you're in your 20s but approaching mid-30s I'd rather not be flashing my bottom. What I particularly like about these skorts is the ball pockets as it's much nicer to have somewhere specific to keep the balls as opposed to tucking them under the shorts.
There's only one shade that matters. I love these pale grey shorts. They bring back happy memories of when I was younger and Adidas have certainly come up with a style that is just perfect: Loose fitting, correct length and light to wear. They have become my holiday must have and cannot tell you how comfortable they are... try them yourself.