Each theme within Plato is an isolated folder containing layout files and CSS which can be used to provide a unique look & feel for each theme.
The default themes for Plato can be found within the
Themes folder. You can see below the two default themes "Default" and "Dark" offered with Plato...
This is the default theme for all new Plato installations. The the default folder contains the light theme for Plato.
This is an optional Bootstrap 4 dark theme.
You can set the default theme for Plato via the General Settings page.
NOTE If the Plato.Theming module is enabled the theme selection available via the general settings page will only show custom themes you've created with Plato.Theming and won't show the two default themes. The two default themes will only be available for selection if Plato.Theming is disabled.
To learn more about the files included within each theme folder please see Theme files.