It was only as I sketched this that I realised how little I must use my earth colours. I like alizarin a lot, and cadmium yellow, and of course, cerulean blue. I must use a lot of ultramarine too as it is quite empty. My lemon yellow is very mucky and I have to buy some more sap green . There is just a little left. The waterbrush is fantastic- I bought three sizes but really only like the fat one.Quite a revealing exercise!