Hello, I try to create a formatter that can display logging messages (or just prints the severity level in different colors). Given a format string like: default_formatter = "%SeverityFormat% %Message%"; /// A custom formatter that handles the Severity formatting class severity_formatter_factory : public boost::log::formatter_factory<char> { public: formatter_type create_formatter(boost::log::attribute_name const& name, args_map const& args) { namespace expr = boost::log::expressions; return expr::stream << "|" << "\033[32m" << expr::attr("Severity") << "|"; } }; and register with bl::register_formatter_factory("SeverityFormat", boost::make_shared()); it basically works, i.e. the output is colored (all green) and the severity name is printed. But how can I get the actual severity of the message that is about to be formatted inside the formatter? So I can act on that and color warn messages red and info messages green? What I found on the internets, e.g. https://stackoverflow.com/questions/38309479/how-to-add-color-coding-to-boos... http://www.boost.org/doc/libs/1_64_0/libs/log/doc/html/log/tutorial/formatte... was using the sink->set_formatter method, which gives me, afaik, no possbility to configure using a format string. But I'm open to any ideas... Thanks, Florian