Coloured with watercolour paint, mostly from Winsor and Newton brand, but also some from Van Gogh. This book luckly can take quite a bit of water, but I find the book so gorgeous that I am often a bit overwhelmed to start on a page. I just really want to do the pages justice.
I personally am really impressed with the professional line from Winsor & Newton. But if you're just starting out with watercolor and want a decent quality paint the Cotman line is also pretty brilliant.
This beginner set is quite good I think.
This is the Van Gogh set I have (though I managed to get my hands on a used set through marktplaats).
The magic in water colour paint is in the brushes anyways. When I started I used brushes from Action (a discount store in the Netherlands), but I can tell you that when I finally caved and got a good aquarel brush....what a difference. The brushes simply distribute the paint a million times better and they also hold a lot more fluid so you can keep going longer when you load up your brush.
And even with cheap paint, as long as you have a good brush you can work really pleasantly.
These are my favourite brushes. Not cheap, but totally worth it.
In the end I used some Pentel Dual Metallic gel pen for the stars and her hair, and I am quite satisfied with how this turned out!