1. A method for extracting a pattern of a specific color from an object containing a plurality of color patterns, the method comprising the steps of: collecting data relating to color components R (Red), G (Green) and B (Blue)from the object; converting the data collected in the collecting step into chromaticity coordinates x, y and luminous reflectance Y; converting the chromaticity coordinates x, y and luminous reflectance Y into Munsell color data H (Hue), V (Value) and C (Chroma); and extracting a pattern of a specific color from the object based on the Munsell color data, the extraction including the steps of: preparing a histogram based on the Munsell color data H, V and C; defining a principal axis for the histogram where variance becomes maximum; obtaining one-dimensional data by projecting the histogram against the principal axis; and selecting a threshold value for dividing the one-dimensional data into at least two groups respectively corresponding to different colors.