I am color blind myself and an airline pilot it is no big deal. I ran into the same thought when I found out when I got my first medical. All your son needs to get is a "SODA" statement of demonstrated ability from the faa. What the do is go out on the ramp and shine the light gun from the tower. If he sees the red light and green are different then he's good to go. It is that easy. Then when he goes and sees the doctor he shows this SODA to him so he's exempt from that test. I am what they call "RED GREEN" deficent. I have no problem see red and green just the test the doctor gave me. As far as the Military I have no idea what to tell you except just so everyone knows COLOR BLIND PEOPLE DON'T SEE IN BLACK AND WHITE! I just think we would be back interior decorators. PM me if you have any more questions and don't worry about it.