Installing Themes
A themes is a plugin with templates. They are published with a -theme prefix.
You can search for themes in plugins directory.
The installation is the same as a plugin installation, through the file book.json:
{
    "plugins": ["theme-official"]
}
On the terminal:
$ gitbook install
$ gitbook serve
In the browser, your book will have a new visual.
Theme-official

Theme-material

Themes configuration
Some themes allows configuration, look at the theme's documentation for more information.
Example https://plugins.gitbook.com/plugin/theme-api
book.json
{
    "plugins": ["theme-api"],
    "pluginsConfig": {
        "theme-api": {
            "theme": "dark"
        }
    }
}
Disable plugins
Some themes, to work properly, require to disable some plugins. To disable a plugin just add a "-" before it's name.
Look at the theme documentation for more information.
Example https://plugins.gitbook.com/plugin/theme-material
book.json
{
    "plugins": [
        "theme-material",
        "-autotheme",
        "-fancybox",
        "-lunr",
        "-fontsettings",
        "-sharing",
        "-search"
    ]
}
Notice that even if you didn't installed any plugin explicitly, some default plugins are automatically loaded.
