LONDON (Reuters) - Sebastian Vettel gave Ferrari's new Formula One car his seal of approval on Friday, while warning fans not to expect too much from a team that made major changes after failing to win anything last year.

"Obviously there is a change in colour for me so it's a new experience but I think the car looks beautiful," said the four-time world champion, who has joined from Red Bull, after the SF15-T car was unveiled online.

"There is a lot of change going on, a lot of new people in new positions including myself, and it always takes a bit of time to settle in," added the German in an interview on the Ferrari website (www.ferrari.com). "I'm confident that we are going in the right direction but I think it would be wrong to immediately expect a lot of us."

Ferrari, the most successful and oldest team, finished fourth last year as dominant Mercedes won 16 of the 19 races.

Red Bull's Australian Daniel Ricciardo took the others and eclipsed Vettel along the way.

"We need to remember we are coming from a 2014 season where there was one team very dominant so it will be difficult to be right there from the beginning," Vettel said. "I think for us the main target is to start to really work together, start to make progress and hopefully catch up more and more as the season progresses.

"If the situation is like last year, it will be very difficult to really fight for victories but of course it is our goal and that's why we're here."

Vettel, who has replaced Spaniard Fernando Alonso in the line-up, joins Finland's 2007 world champion Kimi Raikkonen at a team that had three team principals during the course of last season.

The latest, Maurizio Arrivabene, took over in November and said last month that he would be happy if Ferrari won two races this year. "I am just realistic," he said on Friday. "We are committed at least to win two races."

The Italian said the new car, with a swooping nose in place of the "broken" 2014 one, certainly looked a winner. "Enzo Ferrari said a long time ago that the best car is a winning car. Last year we had an ugly car that was a non-winning car. I like this year's car... I don't know about the performance but it's really sexy," he said.