I do not like the grey either, it is sad and boring,
but in these circumstances it was the most suitable, black or gray thing.
Everything is too recent, still there is a mourning and it is good that it expresses. The color of the clothes is in the habit of being a good form of express it, last Tuesday in the funeral they all were going of rigorous black.
The flags of the Vatican that existed in the place were decorated by black crapes.
Besides, in this case the Princes were the accompanists, secondary figures. The protagonist was the Pope, they had to have a discreet appel.
It is not easy for the women to choose clothes for this type of acts. For the most private and familiar acts with the Pope, it is easier, but for the most formal and official acts with religious authorities it is more difficult. For example, it is considered to be a lack of education that a woman should represent dressed of red to a meeting with a cardinal, because the color of the cardinals is the red one. In the meetings with the Pope in the Vatican the women must go dressed in black, only the catholic Queens can go of white. There are many rules of this type, and to choose the suitable thing must be dificult.