Value refers to the relative lightness (white) or darkness (black) of an element, and has considerable effect on the perceived weight, prominence, and position of that element. Differences in value create contrast, which is an excellent way to force a visual hierarchy (i.e. an order of importance). For example, in the below illustration, though the circle is subordinate to the other shapes in terms of scale and positioning, it nonetheless is the most prominent and ‘heavy’ object due to its dark values contrasting with the light values of the other shapes: