I recall reading that by about 1965 or so, NHL hockey games began to be broadcast in colour on both NBC and CBC (Canadian Broadcasting Corporation). You wonder though if local broadcasts of Rangers or Bruins games were done in colour that bit earlier.
I went away to college in Sept 1964. But I was home often enough and enough of Ranger fan that I probably watched more than a few games back then. (My first weekend home from college included attendance at a Giant game and at a Ranger game!) Ranger Games were mostly only on TV on Saturday nights and only on a local independent station (WOR-9). I don't recall these games being telecast in color though it is possible that at some point the Hockey Night in Canada feeds started telecasting in color and WOR might have used these. By the 1967-68 season, my parents had moved to Manhattan (from Long Island) and we had Cable including everything from MSG. I'm pretty sure all the games were telecast in color by then.
ML/NJ