Yeah I've never heard the color-blind angle either. I've always heard the TV colors were created because of the improved contrast with blue tournament cloth for TV's.
Remember that analog TV back then was standard definition at much lower resolution than we're used to today. Not only was the resolution lower, but CRTs were incapable of the sharpness of modern LCDs and were subject to color convergence problems which resulted in ghosted edges and washed out, distorted colors. So tweaking the colors for TV made sense back then. With today's technology, I'd agree that there's much less need for special TV colored balls.
Remember that analog TV back then was standard definition at much lower resolution than we're used to today. Not only was the resolution lower, but CRTs were incapable of the sharpness of modern LCDs and were subject to color convergence problems which resulted in ghosted edges and washed out, distorted colors. So tweaking the colors for TV made sense back then. With today's technology, I'd agree that there's much less need for special TV colored balls.