"The boots are gray."
Translation:Les bottes sont grises.
is it "grises" because the subject it's describing is plural and feminine?
- The suit is gray = Le costume est gris
- The suits are gray = Les costumes sont gris
- The boot is gray = La botte est grise
- The boots are gray = Les bottes sont grises
Not exactly, its interpretation will depend on context, but it falls in the area of dull, glum, dreary, bleak, drab, etc.
No, est is singular, sont is plural. So if you have des or les you need to use sont.