What property defines how colors blend with layers in graphics?

The property that defines how colors blend with layers in graphics is blending mode. Blending modes determine how the colors of one layer interact with the colors of layers beneath it. They control the way layers combine based on their color values, producing a variety of visual effects that can enhance an image or graphic design.

Opacity, while related to visibility, simply refers to the transparency level of a layer. A lower opacity allows layers beneath to show through, but it does not specifically dictate how the colors interact or blend. Shading pertains more to the way light and shadow are applied to give depth to an object, while contrast deals with the difference in luminance between elements. These concepts are essential in graphic design but do not specifically address the blending of colors across different layers. Thus, blending mode is the most accurate term for describing this process.