Watercolour artist Jane Blundell has just released her new book Watercolour Mixing Charts. It's a 100 page book that contains 98 charts showing mixtures of hundreds of different watercolours.
It's a helpful resource for artists who might want to try out new colours and see how they mix with the colours they already have.
The book's available in digital ebook on Blurb and Apple iTunes store. A physical copy is also sold on a print-on-demand basis but that's a bit pricey.