I've used a colour I haven't used in ages and ages... ultramarine blue. The dragon bowl was a touch different from the other bowls in my collection. The colour just a little more vibrant - something I couldn't quite get right otherwise.
I thought about it and thought about it until I realized I needed a different blue and immediately dug around my paint box and fixed things.
If you look closely, there are hints of ultramarine in other places, so things are nicely balanced.
You can bid on it here.