X-Rite Farnsworth-Munsell Dichotomous D-15 TestX Rite Farnsworth Munsell Dichotomous D 15 Test How it Works Farnsworth Munsell Dichotomous D 15 Test is a two minute screening for extreme cases of common color vision defects: red (protan), green (deutan) or yellow (tritan) color confusion. You'll need a controlled daylight light source such as an X Rite Judge II Color Viewing Booth to correctly administer this test. You arrange one tray of 15 colored caps in hue order. There's a predetermined