Color.Subtract Method (Color, Color)
Assembly: PresentationCore (in PresentationCore.dll)
Color structures are subtracted from one another by subtracting the alpha, red, green, and blue channels of the second color from the alpha, red, green, and blue channels of the first color. For example, the alpha channel of color2 is subtracted from the alpha channel of color1 to produce the alpha channel of the resulting Color structure. The same is done with the red, green, and blue channels to produce the red, green, and blue channels of the new Color structure.
Available since 3.0