Williams will kick off the new decade of Formula One with a revised colour scheme.
The British team, which scored just one point in its worst F1 season to date last year, revealed its 2020 car, the FW43, via an online launch on Monday, two days ahead of the first test on Wednesday.
Title sponsor Rokit, which joined the team last year and extended its deal midway through the year, now has large branding on the sidepods of the car and adding red to the team's blue and white colour scheme.
Last year Williams missed the opening two days of testing after failing to get its car ready on time. When it emerged, the FW42 lacked downforce and was regularly over a second off the pace of the rest of the field.
By Monday morning, the team had already improved on last year by getting the car on track for a filming day at the Circuit de Catalunya.
Deputy team principal, Claire Williams, said her team was viewing 2020 as a chance to rebuild.
"This year marks a fresh start for the team. We have spent time addressing our areas of weakness and have ensured that we have the right people, structures, procedures and resource in place to deliver competitive race cars.
"We are all committed to re-building Williams and returning the team to competitiveness. As such, our 2020 campaign is about making progress. The fighting spirit is still very much alive, and this year, everyone will continue that fight until we get back to where we want to be."
However, design director, Doug McKiernan, made clear that there had not been a fundamental change in the design concept of the car.
"The team at the factory have been working incredibly hard on the development of the car for the 2020 season," he said. "We have paid significant attention to understanding the problem areas of the FW42 and we have carefully chosen parts of the car to develop, those that would give us the most performance for the resources we have.
"The main concept behind the FW43 is that it is a continuous development of the FW42, with no fundamental concept changes to the layout. The most important indicator that we are on the right path will be the level of correlation we have between the tool kit we use to design the car and what the track data is telling us.
"There has been a healthy development rate in the wind tunnel, and we have found reasonable improvements in the cooling efficiency. The team has addressed the mechanical issues that affected it in 2019, these include the brakes and the overall weight of the car. We have made some good progress across these areas and will continue to focus on them during the season."
Chief engineer Adam Carter said the team's decision to stick with some elements of the FW42 meant it could focus on the previous car's main failings -- its aerodynamics.
"The decision to retain some of the core architecture of the FW42 means there has been less resource invested in developing new concepts, which in turn has rewarded the design team with greater bandwidth to optimise their work, evident in both packaging and component detail," Carter said. "By preserving some key parameters, it has allowed for an uninterrupted development programme within aerodynamics in order to maximise the efficiency of the resources.
"As we head towards the pre-season tests and then onto the race season, the most important measure will be the progress relative to our peers, along with our intention of continuing our recent record of reliability. Later this week, we will be looking at our single timed lap pace, our long run pace and the feedback from the drivers to understand where we are and what we do next. We have teams, both at the track and back at Grove, that will be delving into all aspects that define that lap time during the pre-season tests to ensure we are in the best possible place ahead of the first race in Australia."
Mercedes junior driver George Russell remains at the team this season and is joined by Canadian rookie Nicholas Latifi.