The design of present-day color-sensing devices (such as color TV cameras) is generally based on Young's 1801 trichromatic theory as quantified in the CIE system of color mixture. But the actual makeup of the human color-vision mechanism remains unknown to this day. There exists significant evidence that neural hue signals originate from direct rod-cone interaction. We describe a simple opto-electronic device which models a possible neural mechanism for generating such retinal hue signals. The device produces a pulse train simulating the neural hue signal. The frequency of the pulse train varies with changes in stimulus wavelength in a manner similar to the way retinal hue signals are believed to vary. Thus these signals represent primitive hue information extracted from the stimulus.