It's very easy and inexpensive to make your own watercolor paints. Here's a 'how to' taken from my new book Art Spark with homemade watercolor paint recipes and links to famous art example that use paint made from natural ingredients.
How to Make Homemade Watercolour Paints for Kids! Kids can make their own homemade watercolor paints with 5 common, kitchen ingredients! If your kids love simple science activities and art, then they’ll love making these homemade watercolor paints.