No, it's just that some people are so narrow in their tastes that they'd rather see color than black-and-white even if the color version looks greatly inferior in every other respect. Back in the '80s or so, a number of black-and-white Popeye and Warner Bros. cartoons were cheaply reanimated in color by a Korean studio so that they could be sold in syndication. The color versions looked horrible, full of sloppy art and animation errors, and the scenes in some of the Popeye cartoons that used the innovative technique of filming animation-cel characters on glass against a moving 3D tabletop model, so that the background would move with realistic perspective, were replaced with ordinary 2D animation with crude background paintings. The remade versions were artistically inferior in every possible way (well, visually -- they still had the original audio), but they were in color, and somehow that made them far more marketable for the mass audience than the beautifully made black-and-white originals.
Bewitched debuted in 1964. It switched to color for its third season in 1966, around when most shows switched to color. (Well, a year later than Gilligan's Island had switched to color, but the same time Lost in Space did.)