The config item is set dynamically within Themes_model activateTheme method
$this->load->model('Settings_model');
if ($this->Settings_model->addSetting('prefs', 'default_themes', $default_themes, '1')) {
$query = $theme['title'];
}
Config items are stored both in the database settings table and config file.
You can also enable the debug profiler, which will display benchmark and other data at the bottom of your pages for debugging and optimization purposes. This way you can view all the config items, session and server data. To enable open file system/tastyigniter/config/constants.php on line 91 set TI_DEBUG to TRUE
defined('TI_DEBUG') OR define('TI_DEBUG', TRUE);
Also bear in mind that you can now create child themes to override the default theme, as from version 2.1 (yet to be released).
Under Design -> Themes and click the Copy button to create a child theme from the default theme files and data.
After its created, active the child theme to use it on storefront,
then copy the files you want to override from the parent theme to child theme.