Colors may be specified as a named color (red, green, gainsboro, etc.) or as an RGB value specified in Hex form - which is the # sign followed by six digits - each of which can be from 0-F (0-9 and A-F). For example: #000000 (black), #FFFFFF (white), #CCCCCC (a light gray/silver color), #FF0000 (red), #00FF00 (green), #0000FF (blue)