Worked out to the smallest detail: Rectangle coloring page is a coloring book and an exciting travel hobby both in print and online. Choose a coloring mode, from standard coloring using a wide range of tools, to a game by numbers that children will enjoy and improve attention. Share the work of a young artist with family and close friends or keep it as a keepsake. Creative Commons Attribution-NonCommercial 4.0 License. Author of the work: Persimmons Studio.