<%init>
my $current  = RT->Config->Get('WebDefaultThemeMode', $session{'CurrentUser'}) // 'light';
my $new_mode = ( $current eq 'dark' ) ? 'light' : 'dark';

my ($ok, $msg) = $session{'CurrentUser'}->SetPreferences(
    $RT::System => {
        %{ $session{'CurrentUser'}->Preferences($RT::System) || {} },
        WebDefaultThemeMode => $new_mode,
    }
);
RT::Logger->error($msg) unless $ok;

$m->abort();
</%init>
