The Palace Museum has released three volumes of coloring books. [Photo/Weibo]

Color in the Forbidden City, Palace Museum's version of Secret Garden, is now on sale.

The patterns in the book, which is in three volumes, are influenced by palace artifacts, clothing and architecture. All the patterns were hand-drawn by veteran artist Liang Deying, from existing collectables at the Palace Museum.

After the success of best-selling coloring book Secret Garden, in July 2015 the Palace Museum initiated an interactive activity on Weibo through uploading several monochromatic patterns featuring intricate, richly ornamented architecture of its famous structures for people to color in under the tag "Color the Forbidden City".

"The Palace Museum thought about publishing colored photos of architecture in the Forbidden City as early as 2008, because they are aesthetically pleasing, but our thoughts back then were not as 'fashionable' as the coloring idea today. With the popularity of the coloring book, our team thought about trying it with patterns found on architecture," said Guo Ting, who maintains the official Sina Weibo account for the museum.

The patterns were so well received on social media that the museum decided to publish a set of coloring books.

"It may seem like just filling in the blanks with color, but what the readers are really doing repeating the works that artisans did in the past, and that experience is special," said an editor for The Forbidden City Publishing House.