Well I like it a lot better than I thought I would before I saw it on the map.
If you want to change it at all, or make your own version please don't mind me.
I think if anything I made it a little on the dark side overall, but I don't think its a simple case of just making the whole thing a bit lighter because that would make the lighter parts stand out too much against the rest of the pattern.
Have a go yourself, and see if you can't make something even better than that.
All I used was a plain background of the darker colour that I sponged some of the lighter colour over to give it a mottled effect, and then I dabbed the centre with various different circular brushes on several different semi-transparent layers above that.
And thanks for the praise