CMYK is the Cyan, Magenta, Yellow, and Black (key) color model, which are the four colors of ink used in the traditional method of printing hardcopies of images, call offset printing. The CMYK color model is a "subtractive" model. When 100 percent of each color is mixed together, it creates black light. From the Color Chooser window, select the CMYK tab; and the CMYK tab (Figure 1) becomes available.
There are two ways to adjust the cyan, magenta, yellow, black, alpha value of colors. There is a slider bar for Cyan, Magenta, Yellow, Black, and Alpha. Alpha controls the opacity of the color. As you change the slider bar for each one, in the Preview field, the color you are producing is shown. Another way to affect the color is you can directly enter a value in the Cyan, Magenta, Yellow, Black, and Alpha cells. Click OK, and the Color Chooser window will close. Depending on where you accessed the Color Chooser window, you will have to click either Apply or OK for the color change to appear in the display area.