Inserir "CSS" em Classe java

public class GeraHTML
{
    public String getList(List lista) 
    {
        StringBuffer sb = new StringBuffer();
        sb.append("<table width='100%' border='1' cellppading='0' cellspacing='0'>\r\n"
                + "<tr>\r\n"
                + "<td bgcolor='navy' align='center' width='50'><FONT COLOR='white' face='arial' align='center'>Código</td>"
                + "<td bgcolor='navy' align='center'><FONT COLOR='white' face='arial'>Nome</td>"
                + "<td bgcolor='navy' align='center'><FONT COLOR='white' face='arial'>Email</td>"
                + "<td bgcolor='navy' align='center'><FONT COLOR='white' face='arial'>Fone</td>"
                + "<td bgcolor='navy' align='center'><FONT COLOR='white' face='arial'>Sexo</td>"
                + "<td bgcolor='navy' align='center'><FONT COLOR='white' face='arial'>Data</td>"
                + "<td bgcolor='navy' align='center'><FONT COLOR='white' face='arial'>Opção 1</td>"
                + "<td bgcolor='navy' align='center'><FONT COLOR='white' face='arial'>Opção 2</td>\r\n"
                + "</tr>\r\n");
        for (Iterator it = lista.iterator(); it.hasNext();)
        {
            String strDate;
            Cliente cli = (Cliente) it.next();
            strDate = "Null Value";

            if (cli.getDtnasc() != null)
            {
                strDate = new SimpleDateFormat("dd/MM/yyyy").format(cli.getDtnasc());
            }
            sb.append("<tr>\r\n"
                    + "<td align='center'><font face='arial'>" + cli.getId() + "</td>"
                    + "<td><font face='arial' size='3'>" + cli.getNome() + "</td>"
                    + "<td><font face='arial'>" + cli.getEmail() + "</td>"
                    + "<td><font face='arial'>" + cli.getTel() + "</td>"
                    + "<td align='center'><font face='arial'>" + cli.getSexo() + "</td>"
                    + "<td><font face='arial'>" + strDate + "</td>"
                    + "<td><a href=form_atualizar.jsp?cpCodigo=" + cli.getId() + "><font color='orange'>Atualizar</font> </a></td>"
                    + "<td><a href=excluir.jsp?cpCodigo=" + cli.getId() + "><font color='red'> Excluir</font> </a></td>\r\n"
                    + "</tr>\r\n");
        }
        sb.append("</table>");
        return sb.toString();
    }
}