This lovely brochure comes from Pacific Telephone, and advertises their line of extension colorphones. There’s no date on this one, but I think 1960s is a reasonable guess.
The front of the brochure features a delightful mid-century color palette that definitely predates the earth tones of the ’70s. Perhaps someone more versed in commercial artwork of the period can figure out a more precise date range?
Pacific’s full name at the time of this brochure was The Pacific Telephone and Telegraph Company, by which they were known until 1983. That’s the year they moved from their parent company, AT&T, to one of the many new Baby Bells formed in the wake of the former company’s breakup, Pacific Telesis.
Today, the company once known as Pacific Telephone operates as the Pacific Bell Telephone Company, or PacBell. I doubt they offer products as wonderfully colorful or durable as the ones in this brochure.