Basque
Historically, the Basque language did not distinguish between "blue", "green", and "gray", using the term urdin to cover all three. However, present day usage is to reserve the word urdin for "blue", with borrowings from Spanish making up the other two terms (berde from Spanish "verde", green, and gris from Spanish "gris", gray).
Read more about this topic: Distinguishing Blue From Green In Language