FigStyle is a Figma styleguide generator. Simply go to the site, login with your Figma account and then copy and paste the URL of a Figma file into the generator. You can check a box to choose if you want to enable colors, fonts, shadows or gradients. Thats it!
The site then generates a style guide based on your file, breaking down all of the colors, fonts, shadows and gradients used through out. You can share the guide with developers or use the guide to notice where you can streamline your colors, fonts, styles and gradients throughout your file.