Sailor Colors of Four Seasons Spring Waka - Uguisu Ink Bottle. The new Waka - Uguisu is one of the eight colors from Sailor's Colors of Four Seasons collection. This particular color belongs to spring category and brings the picture of lush full greenery of summer. When written with, the Waka - Uguisu ink provides smooth and skip less writing experience and exhilarates the joy of writing. This ink can be used with any standard fountain pen.