Edit: Here is what Lynn Downey, Levi's Historian and Archivist (and dare I say friend in the industry?), has to say about these:
[These are a pair of] juniors jean from the Levi's For Gals line, 1970ish. [...] would have been sold in junior departments of specialty clothing stores. We didn't sell in the big chains like Penneys or Macy's until around 1979. Marketing was mostly at point of sale.
When asked about the logic behind the non-red tabs she replies:
Orange was for fashion jeans, white was generally for Levi's For Gals except it was also for corduroy. Black Tab with gold lettering meant the pants had undergone the STA-PREST process.