private String getCouleur(TypeMessage typeMessage) {
        String classeCSS = null;
        
        if(typeMessage == TypeMessage.ERREUR)
            classeCSS = "rouge";
        else if(typeMessage == TypeMessage.NORMAL)
            classeCSS = "gris";
        else if(typeMessage == TypeMessage.RETARD)
            classeCSS = "orange";
        else if(typeMessage == TypeMessage.AVERTISSEMENT)
            classeCSS = "jaune";
        else if(typeMessage == TypeMessage.IMPORTANT)
            classeCSS = "important";
        
        return classeCSS;
    }