I first saw TAS in glorious b/w first-run on Saturday morning TV in Australia. I certainly didn't see every episode, but I vividly remember "Yesteryear", "The Jihad" and "Albatross", with its Auroral Plague that turned the bridge crew alternating colours - or, at least, shades of grey on our TV. I also would have seen "More Tribbles, More Troubles" before "The Trouble With Tribbles".
Colour TV arrived in March 1975. Not long after, my Dad bought us a colour TV. TAS came to weekday morning TV, one episode per day in "The Super Flying Fun Show". I was determined to catch "the one with the Auroral Plague", so we could enjoy the colours. And pink tribbles?
I must say I didn't really appreciate Lieutenants Arex (even though he changed colours in "Albatross") and M'Ress until reading the Ballantine/Del Rey "Logs" in 1980. By then, TAS had not been on the air for years, so playing catchup was hard. Some episodes were impossible to find, especially "The Slaver Weapon" - I tracked down an off-air VHS copy, but it had no ending! The day I realised that View-Master's "Mr. Spock's Time Trek" reels retold the story of "Yesteryear" in 3D was a triumph!