The question of Blue vestements frequently surfaces around Advent.
In many Anglican and Lutheran parishes blue has become the preferred color for that season on the theory that the penitential preparation for the celebration of the Nativity is of a different character than the preparation for the Paschal celebration.
The unintended consequence is that de-emphasizing penitence during Advent fuels the popular, commerce-driven misconception that Christmas begins at Thanksgiving or possible as soon as Halloween decorations are put away and many a parish has an uphill battle to save the Christmas Carols for the Twelve Days, as some folks would like to sing “Silent Night” right after Thanksgiving.
I think I saw some pictures with blue vestments during Advent somewhere.
I have to chuckle about this because it brings up another thought. One year our church decorating committee decided to get the white poinsettias and do the trees in blue lights.
Our very traditional priest did not like it. LOL!