Nope. They're shown on syndication but on HD. First episode remastered was "Balance of Terror"... Romulan Bird of Prey in HD, baby! You can get these episodes via... ehem... alternative methods... <wink wink>
Aside from the unaired pilot, The Cage, the series was in techni-color.
Actually "The Cage" was shot in colour in 1964. But according to lore the colour print used for editing were damaged. So if anyone got their hands on the copy of "The Cage" to show at conventions and such some parts of it were in 16mm black and white.
Apparently the prints used for "The Menagerie" in 1966 were the undamaged bits.
However, Paramount claimed they found a 35mm colour print of "The Cage" in the 80s and restored the episode for a proper TV airing in 1988. By 1991 when I went to the UK there were colour VHS tapes of "The Cage" as part of the VHS series they have for sale, which I rented to watch from Azad or Global or some video rental shop they had.
The 3rd Season of TOS on DVD includes both the B&W and color versions of "The Cage". To those who have not seen this, it is highly recommended! Chris Pike was captain of the Enterprise here and Spock was the only recognizable crewmember that made the transition to Kirk's crew. And he smiles in this one!!