We put red food coloring in, but it didn't show up until the end. We decided this looks like the clouds of steam and ash you see in pictures.
Completely unrelated, except that I wish C. had been with me when it dropped down right in front of the van this morning:
Another cool thing about NM, you never know what will fall out of the sky. C's whole room is decorated in hot air balloons, so I was really bummed he didn't get to see this one set down. Odds are there will be some tomorrow, though, so we can cause a couple near-accidents on the way to church!