I'm sorry, but I don't have anything on record that would hint at a specific date with any certainty. It has various design elements that span the entire Bonnie Cashin era at COACH, so it's hard to pin down based on observation. If I had to guess, I'd say late 1960s.
I agree with you that the variety of colors that were employed were perhaps revolutionary for the 1960s. Though I believe that I've shared it (somewhere) before, I'm including a color swatch sheet for what my records indicate as being for the Spring-Summer 1965 season. Unfortunately, it's faded, but still provides an idea of the range of colors that were produced. I read somewhere that being a colorist was one of BC's many talents. I can't even begin to tell you just the variations of red that are evident in my own collection of 1960s bags.
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