Liturgical Notes for Christmas

Above all on the day of Christmas, the Gloria should be sung and notrecited.

The normal liturgical color for Christmas is white, but the General Instruction of the Roman Missalalso states in n. 346:

g) On more solemn days, festive, that is, more precious, sacred vestments may be used even if not of the color of the day.
h) The colors gold or silver may be worn on more solemn occasions in the Dioceses of the United States of America.

These liturgical colors draw the parallel between the liturgical Times of Christmas and Easter, the two most important Times around which the Church Year turns.

From Universal Norms on the Liturgical Year and the General Roman Calendar:

32. After the annual celebration of the Paschal Mystery, the Church has no more ancient custom than celebrating the memorial of the Nativity of the Lord and of his first manifestations, and this takes place in Christmas Time.

33. Christmas Time runs from First Vespers (Evening Prayer I) of the Nativity of the Lord up to and including the Sunday after Epiphany or after January 6.

34. The Vigil Mass of the Nativity is used on the evening of December 24, either before or after First.