A standard methodology exists for estimating the flux from front projection displays by sampling the projected illuminance of a white source signal. With the advent and use of white projection primaries, a dramatic increase in flux can be achieved over the red, green, and blue primaries alone. However, saturated-color areas in an image are constrained to low flux levels relative to the display maximum, and hence bright colors cannot be rendered accurately. Because the display of color-accurate imagery does not generally use the white primary, there is a need for providing an equivalent flux measurement that will better describe a projectors color performance when rendering full color imagery. Background research and a method utilizing the source-signal color primaries is described