It may be a bit late for this, but for those of you who want to extend the Christmas Spirit a few days after the fact in your inGraphs this might prove useful. Take a look in the inGraphs UI for the Theme dropdown; it looks like this:
Set it to “Christmas” as in the screenshot above and voila!
It’s not obvious from the screenshot, but those little white dots are animated to give the appearance of falling snow.
Enjoy!