A description on how the set of I Love Lucy was optimized for black and white television.
This knowledge of the contrast secret is further revealed in the décor of the sets. These are painted in various shades of grey. props likewise follow the ethical demands of correct contrast, as do the wardrobes of the players. Even newspapers, when they are to appear in a scene, have to be tinted grey. Such overall uniformity of colors or tones in the scenes make rigid demands on the lighting and has resulted in the careful illumination formula which Freund and his gaffers now regular employ in lighting the sets. (Source)