One of the seasonal tussles of which we see less in some circles thanks to the war on the war on Christmas is over the proper colors for decorations.
As most every Catholic knows, before December 24th evening the right color is somewhere between red and blue on the color wheel. With one Sunday of a color between pink and light grayish-red.
I think a purple with more blue than red alerts us to a somewhat different character of Advent from Lent. Unlike some of my colleagues, I don’t get bent out of shape about blue nor do I feel the need to advocate for it. I wore a lavender/white striped shirt to church today with a blue, green, and red tie slightly suggestive of the 25th of this month. Same tie I wore on my wedding day, btw.
Secular Christmas overtakes this, as we know. In the process of selling product, things are decorated red and green now, with a bit of blue. I know, I know: traditionally green is the color of eternity or viridity or the only outgrowths from tree branches in the Northern Hemisphere. As a liturgy geek, I get used to it during more ordinary times of the year.
Red is associated with Santa Claus. I don’t know if St Nicholas was a cardinal–probably not. He was a bishop. And he did spend time in jail at one point. But I don’t think he was technically a martyr.
White is usually cited as the liturgical color of Christmas. Metallics, silver and gold, seem to have some presence in clergy vestments. I suppose a bit of red or green trim might be okay. In my mind’s eye, I could see a white vestment with red, green, gold, and silver highlights. Maybe a bit much, but Nativity is a feast for indulgence if any liturgical observance is.
Blue as a Christmas color. I saw this mentioned on a secular website. When I was watching one of those Christmas romance movies with my wife last night, the guy had a scene in a goshawful blue sweater. He was in love, so he didn’t care.
Catholic Sensibility 
My favorite vestment of all time was a modern cloth-of-silver chasuble that took on an opalescent quality in the sanctuary at Epiphany. It was a gift, I believe, to a beloved msgr pastor. Cloth of silver is the rarest thing as it can only replace white, while cloth of gold can replace white/red/green, if memory serves.
Blue is something I associate with Chanukah (modern color association) at this time of year. Blue as a royal color is much more derived from the French nation state than Antiquity.
Tyrian purple (and its less pricey imitations) was the royal thing in Western antiquity and First Millennium X’ty.
A bluer shade of dark violet became a substitute for black – as genuine color-stable black was pricey, and most blacks tended to fade to a duller dark bluish black.