The brand colours of red and yellow dominated at Sunday's debut catwalk show, which took place amid the production lines of Ferrari's Maranello base in northern Italy.
Speaking ahead of Saturday’s final practice at the Bahrain Grand Prix, Horner said Ferrari’s decision was encouraging for F1 and everyone involved in the business end of the sport.
The season will kick off with the Austrian Grand Prix at the Red Bull Ring on July 5, followed a week later by a second race at the same track, as part of an eight-race European leg.
Ferrari said 25-year-old Sainz, who replaces four times world champion Sebastian Vettel alongside young Monegasque Charles Leclerc at the sport’s most glamorous team, had signed for 2021 and 2022.
Vettel announced on Tuesday he was quitting the Italian Formula One team, triggering intense speculation as to who would be offered the dream drive alongside Charles Leclerc in 2021.
It's suggested that Carlos Sainz would replace Sebastian Vettel at Ferrar.
The team named no replacement for the German, who dominated F1 with Red Bull before switching to the Italian marque in 2015.
Charles Leclerc had seven pole positions and two wins at the Belgian and Italian Grand Prix.
The 34-year-old Lewis Hamilton, who comes to the end of his Mercedes contract next season, will be bidding for a record-equalling seventh world title in 2020.
The pair, who collided while fighting for fourth place on Sunday, were forced to retire from the race, leaving Ferrari embarrassed and pointless and the drivers arguing about who was to blame.
Sole rival and Mercedes teammate Valtteri Bottas is 64 points behind and Lewis Hamilton needs to score 14 points more than the Finn.
Ferrari have won the last three races, however, and also racked up three pole positions in a row. Hamilton and Bottas failed to finish on the podium at the previous round in Singapore.
“It feels like they are hungrier at the moment,” the five-time world champion told Sky Sports television after finishing fourth in Sunday’s Singapore Grand Prix.
Taking the chequered flag at Monza, Ferrari’s home circuit, in front of tens of thousands of wildly celebrating fans and for his second Formula One victory in eight days, Leclerc was overwhelmed.
Sebastian Vettel came home third ahead of team-mate Charles Leclerc, but both conceded that they could not generate the pace to compete with Hamilton's Mercedes or the Red Bull of second-placed Max Verstappen at the Hungaroring.
Champions Mercedes have won all five races so far this season in one-two formation, with Lewis Hamilton and Valtteri Bottas also taking a fastest lap each.
Ferrari dominated pre-season testing at the Circuit de Catalunya but Mercedes have won every race since then in one-two formation.
Sebastian Vettel and Charles Leclerc dominated pre-season testing at Barcelona’s Circuit de Catalunya amid excited talk of Ferrari ending Mercedes’ five-year stranglehold on the sport.
