(a) Developer gives the appearance of being out of business. Download link doesn't work. However, a little research revealed that the app can be found at <http://colororacle.cartography.ch/>

(b) After installing, a test is the obvious next thing. For some bizarre reason the developer has decided that this app, likely to be used once a year or so,must be a menu commend. There, in glowing multi-hue, is an icon in the menu bar. Click it and choose, for example, "deuteranopia (common). One might hope to then be presented with a display designed to test if the viewer suffers from this affliction. Instead, all you get is a dialog box that says I should click F5 of F6. Pressing either produces...nothing! Now, if this means that I do not suffer from the two afflictions covered by those keys, i should at least see something that enables me to confirm same.

I once had a hard copy book-thing to test for color blindness. It was extremely well-designed and useful. About 50 pages of complex tests. Because of my experience with it, i believe I can conclude that color-blindness is as complex as any other medical problem and this app is a shallow, even glib approach to testing for it. Certainly way inadequate! Not even a hint of a manual, for example.