Different issues.

Zapruder was using 8 mm color film, TV production used larger 16 mm cameras which could film in color too but the TV transmissions were in black and white hence the cameras were most of the time equipped with black and white film rather than color film as it gave better resolution and better shades of gray, black and white than color film converted to black and white during transmission.

Zapruder was an avid amateur photographer and could afford the rather expensive color film. Color film for smaller film formats became available in the 1930's but was so expensive that only very rich people could afford to buy and use it. There is an excellent four part documentary series in color from the 1930's called The Thirties in Colour (episode 1)

It is also worth noting that in 1964, only 3% of households that owned a television, had a color television. By 1968, color TV adoption rate had jumped to nearly 25%. By 1972, it was 52%. By 1990, it was 96%.

So at the time of the Zapruder film, only a tiny fraction of the population owned color televisions. It was difficult for the broadcast networks and affiliates to justify the expense of upgrading to new equipment. All the networks, but one that is.

At the time, NBC was owned by RCA, the prime driver for color television (and owner of most of the patents). So in November 1960 NBC started airing the bulk of its daily broadcasts in color, and by 1965 the vast majority of its primetime programming was in color.

ABC and especially CBS lagged far behind, airing only a handful of programs in color. In 1963, CBS would only air a program in color if the advertisers paid for the added expense. Consequently, they had only three color shows per week.

By 1965, color television reached the tipping point. Color TV sales started to surge, and by the end of that year nearly 10% of the viewing public had color televisions. ABC and CBS finally got on board and both announced they would go all-color for the 1966-1967 season.

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