cards vs rouge et noir

cards and rouge et noir both are nouns.

Word	Noun	Adjective	Verb	Adverb
cards	Yes	No	No	No
rouge et noir	Yes	No	No	No

As nouns, rouge et noir is a hyponym of cards; that is, rouge et noir is a word with a more specific, narrower meaning than cards:

cards: a game played with playing cards
rouge et noir: a card game in which two rows of cards are dealt and players can bet on the color of the cards or on which row will have a count nearer some number

cards (noun)	rouge et noir (noun)
a game played with playing cards	a card game in which two rows of cards are dealt and players can bet on the color of the cards or on which row will have a count nearer some number