The short answer
When there is no Figma file, the client's shipped website is the most reliable design system you have. Extract its real tokens from the live URL, give them to Cursor as a rule it reads on every request, and instruct it to build strictly inside them. The new pages then match the existing brand instead of quietly becoming a redesign.
Why the live site beats a description
Telling Cursor "match the client's brand" gives it nothing concrete, so it defaults to generic. A screenshot helps a little but hides the exact values. The production site, on the other hand, has already committed to a palette, a type scale and a spacing rhythm. Reading those directly means Cursor builds from the client's real decisions, not an approximation of them.
Step by step
- Open the style extractor and paste the client's production URL.
- Extract the tokens: colors ranked and labelled by role, fonts, type scale, radii and shadows.
- Copy them into a .cursor rules file in the project you are building for the client (see below).
- Build in Cursor. Every generation now reads the client's tokens and stays inside their brand.
A client rules block you can paste
Fill in the values the extractor returns for the client's site:
Reuse it across the engagement
Client work usually spans several repos and months. Rebuilding a rules file each time is friction, and it goes stale when the client tweaks their site. The SlopScrub extension saves the client's brand as a taste profile Cursor reads over MCP, and lets you capture specific sections (their real header, their pricing table) for reuse. Point every repo in the engagement at the one profile and the brand stays consistent with nothing to copy by hand.
Where it breaks
Extraction reads rendered styles, so client sites built mostly from images, canvas, or behind a login give thin tokens; capture what you can and fill gaps by asking the client. Tokens carry the look, not the component behavior, so you still specify structure. And this is for authorized client and internal work only: extending a brand you are engaged to work on, not lifting a stranger's site.