FRS Coloring Book is a very simple coloring program that includes 100 illustrations for kids of different age. The application includes illustrations that cover the whole alphabet, basic shapes, the four seasons, numbers, animals, meals, sports, and other interesting topics. The palette in the program is rather poor, it only has one filling size, and it doesn't include any drawing tools. But I liked the fact that every color in the palette produces a piano sound when you click on it (the sound can be disabled, as well as the printing option). Unfortunately, the drawings cannot be saved for kids to continue working on them later.
The trial version of the program allows you to color only five first images (which is nevertheless enough to evaluate the program). In general, FRS Coloring Book is too simple; I think, it may only be interesting for small children. Even for that purpose, though, there are far better similar programs for free out there. The program is also available for Mac OS X.