My short answer is yes, in my opinion they are a quick way to experiment with materials, tools and techniques.
Some books even have special editions for artists, which are printed on heavier paper and hence more adequate to water-based mediums (like watercolors and gouache), pastels or even acrylics.
Some ways I’ve been using adult coloring books:
- Practice color mixes with watercolors;
- Practice the use of water brushes for watercolour painting;
- Practice the use of soft and hard pastels;
- Try water soluble ink for the first time;
- Try gouache paints for the first time.
I currently own two such books: Portoterapia/Portotherapy and Cahier de Coloriages: Amadéo de Souza-Cardoso. Cahier de Coloriages is a french book based on the works of a Portuguese painter — Amadéo de Souza-Cardoso —, and it’s very interesting because it contains a small biography of the artist, the history of each painting and a color reproduction to be used as reference. There are similar books from the same publisher based on works from Picasso, Monet, Klimt and many others.
If you’d like to check the books mentioned above, Portoterapia/Portotherapy can be purchased at this portuguese site and Cahier de Coloriages: Amadéo de Souza-Cardoso at Amazon US | UK | DE | FR | IT | ES.