Indicator provides a basis for indicators designed to interact with an implementation of IGraduatedScale to indicate values that correspond to specific graphical points, determined by the IGraduatedScale. However, it is possible to create an Indicator that does not rely on an instance of IGraduatedScale, and the information needed to indicate specific values would be contained internally. This would be useful when the value system does not correspond to graphical points, such as a color scale system.