The team's 2019 livery was revealed at their Grove base on Monday, with the new light blue, white and black colour scheme a big visual change ahead of a season in which Williams are aiming to rebound from a wretched 2018.
Not much is known yet of the telecommunications company whose products will be launched next month in the United Kingdom and in the US.
"We spent quite a lot of time on this livery", explained Williams deputy team principal Claire Williams.
"We share many similar values and aspirations with ROKiT; primarily putting engineering and innovation at the core of everything we do in our pursuit to be the best - the flawless platform from which to start a partnership".
Williams finished third across 2014/15 and took fifth in 2016/17, and targeted an improvement with its FW41 as it undertook a new design philosophy.
Kendrick, who is the Chairman of ROK Brands, added: "With ROKiT launching in 2019 we wanted a global platform that would help us tell our story of innovation".
"F1 is a shop window to the world so I wanted to come out with a vibrant livery".
A meagre seven points and last place in the Constructors' Championship made 2018 a year to quickly forget for the former multiple champions, with Williams admitting it was "soul-destroying" heading to races with little chance of scoring points.
The Williams looks very different to what it did previous year and perhaps the new look will symbolise new results for the coming season.
The deal was announced during an event at the team's factory - attended by this year's new driver line-up of Robert Kubica and George Russell - and is described as a multi-year agreement. Fingers - and many other body parts - are crossed at Williams that this year's FW42 will be that vehicle.
All they need is a vehicle with a performance level to match the pair's talent.