This is the 5245th most frequent Catalan word.
black
The Catalan word for "black" is "negre."
In this sentence, 'negra' is an adjective describing the color of the noun 'gat' (cat).
El gat és negre.
The cat is black.
Here, 'negra' again functions as an adjective, and agrees in gender with the feminine noun 'pantalla' (screen).
La pantalla del mòbil és negra.
The screen of the cellphone is black.
In this case, 'negre' is used as a noun, referring to the black color as an abstract concept.