I decided to use Sirdar Country Style 4 ply and started off with these four colours: Parchment, Garnet, Soapstone and Purple Sage. They don't have to match the colours on the fabric exactly - near enough is good enough.
Then I looked for shades of those four colours and added three more.
So, there's a darker beige, a bright pink and a deep blue / green (Camel, Rosehip and Prussian). That bright pink isn't really in the fabric but you often need a bolder colour to bring the rest to life. If you look at these two twists of yarn, one without the pink and one with it, I think you'll see what I mean.
Twisting the colours together like this is a good way to see how they'll work together.
So, after all that theory, here's the finished mandala.
It's knitted back and forth and then joined and blocked. I'm hoping that knitters will use this pattern to create their own mandalas in all sorts of wonderful colours.