Is red masculine or feminine in french?

Answer 1

Either. It stays the same for both masculine and feminine words. The only time you add an agreement is if the word is plural. Here you add just an "s", whether the word is masculine plural, or feminine plural.

E.g.

la table rouge - the red table

le sac rouge - the red bag

les livres rouges (masculine plural) - the red books

les fleurs rouges (feminine plural) - the red flowers

Apologies for the lame examples. I picked the first things I could see in my living room...