The Moon is far from monochrome, although the colors are subtle. Also, the hardware and people definitely had color. Color/BW has the same tradeoff on the Moon as the Earth.
On Apollo 12 Conrad and Bean landed very close to Surveyor 3 which had been on the Moon since April 1967. All the pictures of Surveyor are in monochrome because they brought the wrong film from the LEM.
As for why B&W in the first place.....maybe it took longer to get color prints back from the drugstore? This was 1968, after all......
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