Here is a coloured page from my book Through the Kaleidoscope. This full page mandala is coloured in warm green, orange and red, using Tombow brush markers.
Through the Kaleidoscope has 50 original abstract designs, which you can see here. The difficulty level is easy to moderate, so it’s a good book for adults and older kids who don’t like lots of tiny details. You can buy it in paperback from Amazon.
See the Colouring Gallery for more coloured pages from my books.