Looks good to me, in fact my attempt came out slightly darker. There's quite a bit of tomato in it which makes it dark. It's a pretty good base, very much along the lines of Kris Dhillon's, nice and simple, not too many ingredients.
I think if I made it again though I would initially fry the onions in lots of oil before adding any liquid, it seems to add a certain something which I personally prefer.
YF