If trailer views are any indication, the big screen adaptation of IT is going to be a mammoth hit when it opens in September with little to no competition. It is shaping up to be the biggest horror movie of the year, and could pull in monster box office. Enough so that Hollywood will start making even more of these things. The first teaser for Pennywise's big theatrical debut arrived yesterday, and it was received overwhelmingly, with mostly positive reactions from everyone who watched it. But there was one big complete coming from horror fans. Why was that geyser of blood black? Well, there is a reason, and it won't appear that way when the movie opens in theaters.

Andrés Muschietti did the impossible when he delivered his trailer for IT. He didn't disappoint. And people were impressed. But some folks just couldn't get past that black goo flying out of Beverly Marsh's sink. Why wasn't it blood? Well, it was, and is, blood, Bloody Disgusting assures us. But for general audiences, the MPAA wouldn't let it be bright red in the trailer. So it was digitally altered for that particular shot.

Bloody Disgusting got to see the trailer early, when it premiered at the SXSW festival earlier in the month. And at that time, the director warned the crowd that some of the VFX were not yet finished. Muschietti was referring mostly to the geyser of sink blood. In the SXSW trailer, the blood was, in fact, still red, offered up in all its untouched glory for the SXSW masses who'd already gorged themselves on BBQ. But before the trailer could be release to the general public, that red blood had to be CGI'd at the request of the Motion Picture Association of America.

Related: New IT Chapter Two Images Tease Pennywise's Terrifying Showdown with the Losers Club

The MPAA has very strict guidelines when it comes to what you can show in an all-ages green-band trailer. The MPAA's Advertising Administration Rules are as follows.

"Approved (Without Restriction)" forms of film advertisement may not include: Realistic or excessive violence, brutality or scary images, including, but not limited to: depictions of blood or wounds; scenes of torture; dismemberments; mutations or mutilations of bodies (including cadavers); people in jeopardy, including images of people being abused, punched, beaten, bound or gagged; disturbing or frightening scenes, including some transformations and morphing particularly when a character becomes abnormal or grotesque; children in peril, including verbal or physical abuse of children; overt references to or scenes depicting death of a parent or a child; realistic depictions of natural disasters; intense depictions or threats from supernatural creatures or the occult; cruelty to animals; and people or animals on fire (except where, in the opinion of the Advertising Administration, the portrayal is clearly unrealistic to audiences, such as a comic book character)."

That description, for whatever reason, leaves out that fact that no red blood can be depicted on screen either. That's why you don't, and won't ever, see red blood in a horror movie trailer unless it arrives under the red band. And there are circumstances were too much blood in a movie could garner it an NC-17 when it hits theaters, which no studio wants. The loophole seems to be, if the blood isn't red, be it black, green, yellow or any other hue, that's all well and fine by MPAA standards.

IT doesn't hit theaters until September 8, so chances are we'll see a red-band trailer for the R-Rated release arrive sometime between now and then. And it will surely show off some of the gruesome delights awaiting horror fans in this hugely anticipated update of the classic Stephen King story. In IT, seven children known as The Losers' Club come face to face with life problems, bullies, and a monster that takes the shape of a clown called Pennywise.

Bill Skarsgard stars as Pennywise the clown.Members of the Losers' Club include Jaeden Lieberher (as Bill Denbrough), Finn Wolfhard (as Richie Tozier), Jack Dylan Grazer (as Eddie Kaspbrak), Wyatt Oleff (as Stan Uris), Chosen Jacobs (as Mike Hanlon), Sophia Lillis (as Beverly Marsh) and Jeremy Ray Taylor (as Ben Hanscom). The Leper is played by Creature performer Javier Botet, and the trio of bullies tormenting the Losers' Club include Nicholas Hamilton (as Henry Bowers), Owen Teague (as Patrick Hocksetter), Logan Thomspn (as Victor Criss) and Jake Sim (as Belch Huggins). You can take a look at all that black goo, which will be turned bright red soon enough, in the first trailer here, in case you missed it yesterday. Fair warning, its a bit scarier than your average Creepy Clown Sighting!

Cinemark Movie Club
B. Alan Orange