Organic Tricolor Romaine Mix Lettuce 500 Seeds #70391 Item Upc#650348692346 33-40 Days. Organic Tricolor Romaine Mix consists of Vivian, Silvia, and Freckles Organic Romaine lettuce seeds. 500 Seeds - Simply sow this premade mixture and enjoy a bountiful harvest of green and red, super nutritious romaine leaves. Plants can be spaced 6 1/2 by 6 1/2 inches for maximum yields.