By default, once you open your Recurly site the sidebar will be purple. Recurly also provides three other color options as well: teal, blue, and steel grey.
To change your sidebar color, you'll simply click on the Configuration tab and access the site Site Settings page. Then you'll want to scroll to the very bottom of the page to view the Site Customizations, select your Sidebar Theme, see how it looks, and save (or choose another color). It’s that easy.
Note: Only Admin users of Recurly will be able to change the sidebar color, and any changes will apply to all users accessing that Recurly site.