Color sensor to measure single separation, mixed color or IOI patches

A marking engine forms one or more toned patches and/or images on a photoreceptor transfer device such as a photoreceptor belt or drum, either within or outside a main image area. A sensor illuminates the tones patches and/or images on the photoreceptor transfer device using wavelengths outside the photo response range of the photoreceptor transfer device, thereby allowing reflectance values for each toned patch and/or image to be measured without generating ghost images on the photoreceptor transfer device. The sensor supports collection of measured reflectance values from single-color, mixed-color; and multi-separation image-on-image toned patches and/or images directly from the photoreceptor transfer device at rates as high as one or more times per revolution of the photoreceptor transfer device. The measured reflectance values may be used to generate and/or update color stabilization tone reproduction curves.