I Took my class 3 student pilot medical and passed everything but the color vision portion of the test. I found somebody with a farnsworth lantern...took 2 months and passed by the skin of my teeth. I called the FAA Regional medical office and was told that the farnsworth is only acceptable for pilots and Not an ATC. I didn't like that answer so i called their office in OK and was told that it is an acceptable test, just that you have to fail the Dvorine test first and then and only then would the farnsworth be an acceptable substitute. Anybody else jumping through any color vision hoops?