I literally just pulled this out the tank. I would have to wonder if it would die out that quickly. It's not even 24hrs old. I have even pulled out Duckweed in this manner before and the water never turned purple before. Had it sitting for days without a color change. Very, very odd.
We just got back from dinner and it was even darker purple. I drained the container and replaced with fresh tap water. We'll see what happens.