The 1984 Gibson novel Neuromancer begins with the line, "The sky above the port was the color of television tuned to a dead channel."
At the time, this unambiguously meant the speckled gray of analog TV static: radio noise amplified and played out through a CRT's scanning electron gun. However, before too many years had passed, new TVs started displaying a solid blue screen when tuned to a dead channel.
And in 1996, Neil Gaiman riffed on Gibson's line, in Neverwhere: "The sky was the perfect untroubled blue of a television screen, tuned to a dead channel."