To be beautiful and not to be added

The Hanukkah candle is a rabbinical law and there is no reason to add to it. Beyond that, the decoration is part of the regulation of lighting the candle and therefore it does not belong to the rabbinical law. Both because what the sages regulate is not a rabbinical law, and also because here it is part of the rabbinical regulation itself. Furthermore, I believe I have already written here before that the hidur on Chanukah is not a matter of "this is to me and to him," since more than one-third of the mitzvah is hidur. This is hidur from the principle of the law, a remembrance of the hidur that was made possible for us by the miracle (to light with pure oil, even though impurity was permitted in public). I explained that in fact there is an obligation to hidur, but it could not be included as an actual obligation because then they would not do it as hidur.