Starting from 1686-1687 Gregorio De Ferrari was engaged, with his father-in-law Domenico Piola, in the fresco decoration of the second “noble” floor of Palazzo Rosso, commissioned by Gio. Francesco I Brignole - Sale (1643-1694): starting from the hall, passing through the four rooms to the east up to the south loggia facing the sea, a single and consistent iconographic project is developed which has as its central conceit the linking of Apollo god of the Sun, who with his chariot marks the rhythm of the days, and the owner of the house Brignole - Sale, whose heraldic coat of arms, a rampant lion, is the zodiac symbol of summer, the season of the sun.
The decoration of the hall, created by Gregorio De Ferrari is the fulcrum of this complex figurative system, revolving around the mythical figure of Phaethon, son of Apollo. It bears the coats of arms of the patrons, Brignole and his wife Maria Durazzo in the corners: unfortunately this decoration was destroyed due to the bombings of the second world war. Following this we find the lounges dedicated to the allegories of the Four Seasons, iconographically connected to the general symbolic plan as emblems of the passage of time. In the first two rooms, still the work of De Ferrari, Spring and Summer triumph in the centre of two ceiling vaults framed by stucco work by Giacomo Maria Muttone. In the summer room Cerere, goddess of the harvest, flies next to a putto holding a large bundle of golden ears of wheat, prevails over the winter winds driven by the Aura, while the centre of the composition is again dominated by the figure of Apollo the Sun accompanied by a lion, this time allusive also - as already in the hall - to the sign of the zodiac and therefore to the summer, in an amusing play of references both astrological and dynastic.