The Catalan word for black is
negre

Translations for black and their definitions

negre	©
1. adj. ca-adj
2. adj. black (absorbing all light and reflecting none)
3. adj. black, Black (of or relating to any of various ethnic groups having dark pigmentation of the skin)
4. n-m. black (color perceived in the absence of light)
5. n-m. black person
6. n-m. ghostwriter

fosc
1. adj. ca-adj
2. adj. dark (having an absolute or relative lack of light)
3. adj. (of a color) dark (dull or deeper in hue; not bright or light)
verd fosc - dark green
4. adj. dark (conducive to hopelessness; depressing or bleak)