I am of the opinion that winter outfits that are not specifically colored red with white trim should be kept as generic winter outfits/clothing. "X Santa" (where X is blue, green, black or white) just seems... convoluted. IMHO. Good arguments desired.
Side note: No-one would ever call Emma Frost a White Santa.
The red-clothed Santa is an invention of the Coca-Cola company, blue Santa is also common. It's still cosplay if the clothes are changed to the cosplaying character's usual colors (post #551545) and a santa_costume is very much like cosplay. Thankfully, Santa's clothes look nothing like Emma Frost's.
Well if all you're doing is swapping the red with blue, the costume's appearance still remains the same, so it'd still be a Santa outfit. Just because the suit is a different color doesn't mean we don't still recognize what the suit is or is based on.
I looked around, didn't find anything particularly recent on blue Santa Clauses. There is this NPR radio snippet where the director of the American Toy Marvel Museum in Akron, Ohio mentions that blue was the traditional color of the German version of St. Nicolas.
Another one was Ded Moroz or Grandfather Frost, a Slavic version of Santa Claus. Though it seems the wearing of blue costumes might have been due by order in the Soviet Union to prevent him from being seen as Santa Claus.
According to various (yet poorly sourced) online texts:
The real "red revolution" (pun intended) took place in 1931, courtesy of Coca-Cola artist Haddon Sundblom.
This was preceded by the first U.S. Christmas cards, published in 1885 by Louis Prang, likewise presenting a red-clad Santa. Prang's illustrations may have been the earliest milestone on the road from using various colors (blue, brown, gold, gray, green, pink, purple, red, white) towards the domination of red.
According to my own experiences:
In Hungary in the 90s, Mikulás most often wore red but also a number of other colors were possible; in the U.S.S.R. Father Frost (Дед Мороз) wore blue, but in modern Russia, he resembles the Coke Santa more and more often; in Finland, Joulupukki has worn both gray and red in different combinations for long decades, but the previously dominant gray is gradually being forgotten.
It is another question whether non-U.S. Christmastime giftbringers (including Father Christmas) should be regarded as variants of Santa Claus for Danbooru tagging purposes or not.
Is this about the recent color tags? Because that was me, I got bored and went through all the santa_costume pages to see how many common colors with no red showed up, black being the top one (surprisingly). I was trying to think of a better tag like nonered / nored / notred, but they didn't seem right so I just continued. I thought about christmas or holiday outfit, but didn't bother bringing it up in the forums.
I think it's fine as they are. Non-red Santa outfits may not be common or traditional, but they are appear to be exactly the same as standard Santa outfits except for the color. I'd say keep the tags as they are.
alternate_color: Different colored versions of a character's original attire and overall appearance.
That would only work for Santa himself. Most of the time, characters wear x_santa_costumes because the dominant color of their usual clothes is x (Meiling green; Marisa, Mio, Rumia black). post #784566 isn't alternate color either.
EDIT: ...Um, S1eth has a point. Actually one might call them crossovers or something, if they combine common Santa outfit designs with the characters' usual clothing patterns.
On the other hand, who is "Santa himself"? A fictional character "existing" somewhere out there, or a character role played by others, even by fictional characters, with varying degrees of credibility? A broader interpretation of the wiki text just might work in this case.
I am leaving my vote as it is. Let further discussion decide which way to go.
Thought of alternate_color and alternate_santa_costume as well, but just because red is common with the west it doesn't mean it is a traditional color with everyone else. And I do believe it would work best for Santa not holiday things.
EDIT This depends on what the tag is being used for in the first place, is it Santa Costume as in following the red, white trim with puff balls or the theme in itself?
Non-red outfits can be santa_costume, but the bar is a lot higher for what goes under it. Red with white trim (especially in a winter scene) is many times going to fall pretty clearly under santa_outfit but other colors with white trim need to look a lot closer to the basic ideal to fit, I think.
I mean, post #844706 was under santa_outfit. I've removed it. If it were red, maybe the argument would be a little stronger but with blue it really looks like it could be anything.
Not because "red is better" but because it's simply a fact that most people nowadays, in the places of the world that contribute danbooru-relevant fanart, think of red as Santa's color.
At any rate it's going to be something decided on a case by case basis and we're not going to all agree on every one.