Based on the novel, by Eto Mori, Colorful is made by the veteran animation director Keiichi Hara. The movie was a project suggested by Sunrise's president Kenji Uchida to director Hara, and took five years in the making, beginning from their first meeting.
The movie is absolutely stunning in its production. I give lot of credit to director Hara for all the attention to details he's put in. His experience shows, and his clout in collecting the best talent is also evident in the people he's gathered to make this movie.
You really need to see this movie to appreciate the story, and the artistry. Never since the days of original Disney's animation, have an old school animation movie made with such high level of artistry.
This is a modern day classic, and worth every minute of your time to see it.