Hi, a quick response, bit pressed for time.
There is an image of one of these vases, in the flesh, with production number. Vase in sommerso, purple/amethyst over blue. Drawings show vases red over blue and yellow/ the reverse order, and a vase with colour inclusion to the base, and both vase no 2892-340 and the drawings are for cylindrical vases.
Can't post images for copyright reasons.