The Design Lab for our Nimble responsive theme has been out to our Beta users for a while now, and we're hoping to get that out to all users later this year. As we work our way toward that goal, we invite our users to request specific features or style options they would like to see made available in the Design Lab.
Are you looking for additional font options? Are there style changes you wish to make that aren't doable without adding your own CSS customizations? Tell us all about it, either in the comments below or via a help ticket within your account. We'd love to be able to integrate your requests so that we can make the Design Lab well-rounded; and you can use it to its fullest potential for your blog.