This file format is used as a canvas (background) in a variety of image editing software in order to set the main color of the image. It is used to fill the canvas with one solid color. It belongs to the group of 'pseudo-image' file formats. It can be used for the fill color, which is chosen from the selected area in a particular image.
This format was created by Nokia for use in its proprietary phones. A bitmap image was used to transfer image files between devices over a wireless connection. It was mainly used when exchanging multimedia text messages that support inserting pictures.