Digital video recorders record and store video camera output in digital form on disk. These recorders can typically record from several video cameras simultaneously and can have features such as event or alarm triggering, searching ability, and adjustable frame capture rate.  Digital video recorders can be in either monochrome or color format.  Monochrome, or grayscale images are presented in black, white, and grayscale.  Color format presents the image in color.  The range of colors is generated with varying combinations of different discrete colors.  One common technique is sensing the red, green, and blue components (RGB) and combining them to create a wide spectrum of colors.