Photoshop Tutorials - CMY and CMYK Color Model
CMY and CMYK Color Models
CMY color model depicts reflected colors. They are generated as the result of subtracting the parts of the thrown light spectrum and are called subtractive colors. When two colors are mixed in CMY, the result is darker then both initial colors, as each initial color absorb part of the spectrum. In other words, the more paint is placed the more is subtracted from white color, so the total brightness will be less.
Let us decipher the name of the CMY color model. C is for Cyan, M is for Magenta and Y is for yellow. CMY channels are the results subtracting the basic colors from the white color in RGB color model. These equations show how each color is formed in CMY color model:
Cyan = White - Red
Magenta = White - Green
Yellow = White - Blue
CMY model is the inverse of the RGB model. As you can see the basic colors of CMY are located opposite to the RGB colors in the color scheme image. According to the RGB color model, white color is the sum of three components of the maximum brightness:
White = Red + Green + Blue.
Now after simple calculating we can see how CMY works:
Cyan = Green + Blue
Magenta= Red + Blue
Yellow = Red + Green
You can figure this out comparing the images of these two color models.
CMYK color model evolved from CMY. It depicts the real process of the image print with computer printer or any other printing equipment. Magenta, blue and yellow paints are plotted on the paper in different proportions allowing to reproduce the bigger part of the spectrum. Black and dark areas are created with black paint and not by mixing the colors to receive black as the result. Black color (paint) is the fourth element of CMYK. CMYK is a four-channel color model. Why plot black color separately? Real paint contains admixtures unlike the light and mixing them you will receive dark brown and not black. In addition, you would have to plot great amount of paint over the area you want painted in black or dark colors, the paper would become too moistened and you would need to spend more paint.
These color models are device-dependent. When the same image is depicted using two different devices (for example computer monitors) most likely you will receive slightly different results. Therefore, the color depends on the values of color components in Photoshop and the device used to display the image.