Although using a theme is simple, creating a theme that can work across the entire library of page designs requires highly advanced skills.
PageTiger's creative team can do this for you. They'll simply ask for your brand guidelines then come back with suggested font and colour options before building the theme and adding it to your Account.
Once built, your theme can be shared across any other Accounts in your organisation and used with any templates or pages from the layout library for which it was created.
In general, dependent on the complexity of your requirement, a theme will take one Studio Day plus any font costs if you are unable to supply the font(s).