Rule 25(c) allows any sailing vessel to carry, in addition to sidelights and sternlight, red over green all-round lights.
Annex I para 2 specifies the vertical positioning and spacing of lights. On a vessel less than 20 meters vertical lights must be spaced at least 1 meter and the lower light must be at least 2 meters above the deck.
BTW, the tricolor is legal for vessels under 20m in length. Is yours larger?