She heard him out in the kitchen when the music stopped. She heard him go to the piano and plink with two fingers a tune whose name she did not know but which she had surely heard from the radio in Vicki’s room. ‘Tsk,’ she said. ‘He would play that kind of stuff.’ She stepped into the passage, thinking herself safe and superior; but he struck one quiet chord, a wide blue one, a chord from the kind of music she knew nothing about and was too tight to play; she stood still, listening, and he left a silence, and then he resolved it.
I was reading a novel that I came across this: quiet chord, a wide blue one
Does "quiet chord" mean "minor chord"?
And does "wide blue one" mean "keys that are blue and wider than other keys"?
Do keys in piano have different colors?
Source: This passage is from The Children's Bach by Helen Garner