In the original concept art for The Devil's Playhouse, artist Ryan Jones drew Sam carrying the famous demon broth. As you can see, the broth is clearly green.
When the game arrived, what color was the broth? Well, I can't remember, but I guess not green, since Skunkape announced on their Twitter that their upcoming remaster has fixed that mistake.
No word yet on release date, but rest assured the team are working hard. It's going to be worth the wait.