You can link your project to a styleguide to inherit colors, text styles and components. When you link your project, you can see the colors, text styles and components that are defined in that styleguide (and its parent styleguides) under your project's “Styleguide” tab.
Linking a project
From the Styleguide tab of your project, click on “Link to Styleguide”. Zeplin will list the styleguides available.
☝️ You can link a project only to one styleguide, but it will inherit resources both from the linked styleguide and its parents.