This is another coloured page from my fifth colouring book, Through the Kaleidoscope. The illustrations in this book are basically full page abstract mandalas, and you can see them all here.
This design is one of my favourites from the book, and I coloured it in a limited palette of grey, purple and turquoise blue, using Tombow brush markers.
Through the Kaleidoscope has fifty illustrations, and most are moderately detailed, making it a good choice for older kids as well as adults. You can buy the book in paperback on Amazon.