A color machine vision system with two or more differently colored light sources and one black and white photoelectric sensor (BW sensor). The light sources are employed to separately illuminate a target object with a different color, e.g., red, green, blue, magenta, yellow, and cyan. The BW sensor senses the reflection of colored light off the target object from each light source. A separate measurement is generated by the BW sensor for the reflected colored light from each light source and stored for further processing to render a color image of the target object. A calibration is performed to enable the BW sensor to sense reflected colored light from the target object in a linear mode, not the non-linear (saturated) mode. Since calibration enables the BW sensor's electronic components to operate (sense reflected primary colored light) in a relatively linear mode, the sensor is relatively accurate and fast in alternatively sensing/measuring reflected primary colored light from each of the light sources.