The Mass on an anniversary of the death of a loved one is supposed to be offered at your parish at your request. It may not be able to be offered on the day of the anniversary, but provisions should be made to offer the Mass as close as possible to the anniversary of the death.
At this Mass, the deceased is to be mentioned 4 times - during the opening prayer, during the prayer over the gifts, in the Eucharistic Prayer, and in the closing prayer. The deceased could also be optionally named a fifth time in the petitions.
In addition, the person requesting the Mass is supposed to have the option to have the Mass said with the priest wearing black, white, or a violet vestment, and it is supposed to be up to the person requesting the Mass, NOT according to what color the priest happens to like or not like.
It should be noted that in the typical American parish, if you went in and asked to have a Mass said for a deceased loved one or friend on the anniversary of their death, and you requested that the priest wear a black vestment, you should prepare to be assaulted by the priest.
Nonetheless, a Mass for the dead, using the prayers in the Missal for such an occasion, including the Eucharistic Prayer, with the priest wearing either white, violet or black is what the Church clearly envisions.
As the General Instruction of the Roman Missal notes in paragraph 346, part e)
"Besides the color violet, the colors white or black may be used at funeral services and at
other Offices and Masses for the Dead in the Dioceses of the United States of America."
The Mass is not more "beneficial for the deceased" because their name is mentioned more frequently at this anniversary Mass for the dead, but it is more comforting for those of us left behind to hear our loved one mentioned by name in the prayers of the Mass.
I am saddened that priests who are touted as having a "hugely pastoral heart" will often refuse to offer anniversary Masses for the dead, even though they often bring much more comfort to the living than simply seeing their loved one printed in the bulletin as the Mass intention for the day.
Pope Benedict: "Maybe because death is sad, and the Church is okay with sadness."
Not all tears are bad - J.R.R. Tolkien