The phrase refers to printable or digital sheets featuring graphic and violent imagery drawn in a style reminiscent of Japanese animation, intended to be colored. These illustrations frequently depict scenes of blood, injury, and other potentially disturbing content common in certain genres of Japanese animation. These visuals are adapted for the creative activity of coloring, typically aimed at an older or more mature audience.
The appeal of these illustrations lies in their unique blend of artistic expression and engagement with darker themes. The act of coloring can be a therapeutic or stress-relieving activity, even when the subject matter is intense. Historically, coloring books have been a medium for self-expression and creative exploration. The inclusion of extreme or violent themes expands the boundaries of the art form and potentially caters to a specific niche with an interest in macabre aesthetics.