All cats are gray at night

Meaning: When darkness obscures differences, all things appear equal or indistinguishable.

Origin: John Heywood's 1546 collection has "When all candles be out, all cats be grey" — in the dark, differences of color vanish. It was often said with a wink, to suggest that looks matter little by night, and the same saying exists in French, German and Spanish.

Equivalents in French, Spanish, Japanese, German, Portuguese, and 3 more languages

French: La nuit, tous les chats sont gris (literally: At night, all cats are gray)
Spanish: De noche, todos los gatos son pardos (literally: At night, all cats are gray)
Japanese: 夜目遠目笠の内 (Yome tōme kasa no uchi) (literally: Seen at night, seen from afar, or seen under a hat)
German: Bei Nacht sind alle Katzen grau (literally: At night all cats are gray)
Portuguese: De noite todos os gatos são pardos (literally: At night all cats are gray)
Dutch: Bij nacht zijn alle katten grauw (literally: At night all cats are gray)
Russian: Ночью все кошки серы (Noch'yu vse koshki sery) (literally: At night all cats are gray)
Polish: W nocy wszystkie koty są czarne (literally: At night all cats are black)