Yes, it is on default skin. Most of the settings for RoundCube are default settings except these:
+$rcmail_config['default_host'] = 'mail.domain.com';
+$rcmail_config['smtp_server'] = 'smtp.domain.com';
+$rcmail_config['mail_domain'] = 'domain.com';
+$rcmail_config['dont_override'] = array('display_next');
+$rcmail_config['plugins'] = array("markasjunk2","lang_sel","compose_addressbook","compose_newwindow","limit_recipients");
+$rcmail_config['drafts_mbox'] = 'INBOX.Drafts';
+$rcmail_config['junk_mbox'] = 'INBOX.Spam';
+$rcmail_config['sent_mbox'] = 'INBOX.Sent';
+$rcmail_config['trash_mbox'] = 'INBOX.Trash';
+$rcmail_config['default_imap_folders'] = array('INBOX', 'INBOX.Drafts', 'INBOX.Sent', 'INBOX.Spam', 'INBOX.Trash');
+$rcmail_config['spellcheck_engine'] = 'pspell';
+$rcmail_config['spellcheck_languages'] = array('en'=>'English');
+$rcmail_config['preview_pane'] = true;
+$rcmail_config['display_next'] = true;
Some post said that it requires GD with GIF support. Is it the case? I didn't find the GIF support for current GD.