Bradbury repeatedly uses the color gray to describe the parlor. He chooses this color to show the depressing nature of the parlor. He sees the viewing parlor as a way for people to turn off from experiencing life and the world around them. All the vibrancy of life is drained out.
In contrast when he talks about the park he uses the color green. Green symbolizes life, growth, vitality. He's showing that society has become dull and miserable inside their homes instead of alive and joyous in the world.
Well if it was me i would bring up points about telephones being used in these places for many reasons such as communicating with others such as if you were in a store and you wanted to see if someone liked something and for other things such as emergencies such as if you were being followed or were in any life threatening situation. sorry if this doesn’t help