According to https://minecraft.gamepedia.com trapped chests have used the Christmas texture since 1.8.9 and Ender chests have used it since 1.13. I do love the Christmas but it is impossible to tell which chest I am looking at.

It would be cool if the Ender chest turned into a purple present for Christmas and if the trapped chest could have some sort of marking around the lock like how the trapped chest looks when it isn't Christmas.