Official looking, professional in style.
Main colours are white (mainly), maroon, and light grey.
Photos of british passports (from e.g. getty, or shutterstock etc), typo: arial or calibri, lots of icons to help display the process and make it user friendly,
Also, quite important is if the top half of the website (up to where the 'Still have a question' comes, this is to be the main dominant 'coloured' area. Beneath that it can be more whitish.
Also, from the template provided > it appears very 'boxy'; this is just for the designers reference. Please kindly have the landing page spaced out, very spacious in formatting, and very considerate of the site structure of it. Spacious, and easy on the eye, not compact.