Didactic Scientific convenient benchtop comparator is a three-field instrument for visually determining the color of samples by direct comparison with colored glass filters. For rapid color grading within predetermined color limits, the glasses can be set to the two limiting colors, making it easy to see if the sample is within tolerance. With a 3-section field of view, the sample and two consecutive glasses on the color scale are viewed simultaneously, making it easier to achieve the optimal color match.