There are two methods available for accessing the Template Manager: Cutomise Template. The Cutomise Template interface allows for editing the actual code found in the template files, creating layout overrides and template file manipulation.
Styles refers to changing the available parameters of a template, such as color, font-color, logo, etc. These are dependent on the parameters a template maker made available and are a convenience for quick changes.
To access the Template Cutomise feature:
You should now be looking at the image below, Template Manager: Cutomise Template.