There's no difference - in fact, "limed mahogany" seems to be the official name:
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:salude
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It looks like "TV Yellow" is a popular slang name for the finish, probably because they called the guitars (Juniors and Specials) with Limed Mahogany finish the "TV Model" (in the brochure you linked to). I've heard both terms before, but that makes sense. Funny, though, Gibson has used the term "TV Yellow" in the modern era for guitars with that finish, I don't think they use "Limed Mahogany" at all these days.
I read that they called those guitars the TV models because the brighter finish was supposed to show up better on television (which was black and white back then).
Al