The Red Beverage in The Stand Adaptation (1994) Ep. 1

There is a scene in which the deaf mute character is minding the jail. He takes a tray of food over to a jail cell and hands the inmate a drink through the bars. I assume the drink is in a paper cup.. The inmate Ray takes the cup through the bars of his cell and then hurls it against a wall. The drink splatters thick and red on the wall. It reminds me of fake blood. That's just weird and not what a soda drink looks like. Is it a "Slushy?" Is there some obtuse meaning in it, or am I making too much of it? I am just now watching the series for the first time, and have never read the book, so PLEASE if the answer involves spoilers, either warn me or don't post it.

Thanks.