When we indicate or describe an object in everyday lives we often use a color of the object. Although there are a million of colors around us we do not use so many colors, but categorize defferent colors into several color names. Eleven color names; red, green, yellow, blue, brown, orange, purple, pink, white, black and gray, have been qualified as basic color categories, that are used consistently among observers and occasions. In this study we measured categorical regions in a color space determined with a categorical color naming method using these 11 besic color names. Two color-appearance modes; aperture color mode and surface color mode, were tested. We employed both a color CRT monitor and a OSA uniform color scales set as test stimuli in the two color-appearance modes. It is shown in our results that both aperture and surface color spaces were consistently divided into the 11 basic color categories, and that positions and borders of color categories depend on luminance (lightness) of test stimuli in the surface color mode, but almost independent on luminance in the aperture color mode. Furthermore, test stimuli made by a color CRT do not appear so different from those by color chips in both color-appearance modes. There are some similarities between our results and the Kelly's chart.