"The sky above the port was the color of television, tuned to a dead channel."
The sky was gray, like the black/white snow on a TV appears gray from across the room. And I'd guess it's given praise because it uses a technological metaphor with a cynical or depressed slant rather than comparing it to something naturalistic or otherwise trite. It also illustrates the superceding of reality by virtual reality. The television isn't the color of the sky - the sky is the color of television.
"The color of television".
"The color television" has probably been said a trillion times. "The color of television" was probably the first time.
I don't think it's the greatest line, but it's got its merits.
-- Plus, it probably makes lit critters happy for recalling Eliot's
Let us go then, you and I,
When the evening is spread out against the sky
Like a patient etherized upon a table;
in the sense of bringing a crashing sense of cognitive dissonance with a modernistic/naturalistic unusual simile (here).