Biyee color vision deficiency (a.k.a. color blindness) tests are based on research work originally carried out in the early 1990s at Cornell University. They were brought on-line in 2000. The online version (https://www.biyee.net/color-science/color-vision-test/) has been used by millions of people all over the world. It has also been used by organizations to screening job candidates. They are based on the same principles as Ishihara plates used by optometrists, but use test plates that are randomly and accurately generated at run time. This is different from many other tests using scanned or static images that can be grossly inaccurate. The prevalence of color vision deficiency is about 5%. Most of them are caused by the missing or defect of one of the three cones in the retina responsible for color vision. If one cone is missing, it is called dichromacy which has three types corresponding to the three cones (protanopia, deuteranopia, tritanopia to L-, M-, S-cone respectively). If one cone is defective, it is called anomalous trichromacy also with three types corresponding to the three cones (protanomaly, deuteranomaly, and tritanomaly). This app is intended to identify these color vision deficiencies.