Step1. Sign in pubhtml5.com.
You can sign in with your existing social media accounts, such as Facebook and Google. Of course, if you have a PubHTML5 account, you can sign in with your account immediately, if not, you can also sign up to log in your account.
Step2. Find the book you want to design.
Choose one book folder in "MY PUBS" and then click the "General setting" button to enter the BOOK SETTING interface.
Step3. Click "ADVANCED-Main" buttons in sequence firstly and then click "Loading Caption" and "Caption color" to change the caption text and color.