Movie Trailer Facts

The color of the background for movie rating cards is important. The rating for the film itself shows up in text, but is also indicated by the background color of the rating card splash screen.
There are three colors used - red, yellow, and green. The specific regulations surrounding what can be shown in the preview for each of these rating cards are set by the MPAA.
The most commonly seen one is the green rating card. Before April of 2009, a green background meant that the preview was approved for all audiences. Since April of 2009, the MPAA now states that the green card is for “appropriate audiences”. This basically means it is appropriate for audiences in theaters, taking into account what movie the audience is about to watch.
A yellow rating card indicates the preview is for age-appropriate Internet viewers and is used on internet trailers only. The red rating card indicates that content in the preview is only appropriate for mature audiences. These previews can only be shown in theaters where the movie about to be watched is R-rated, NC-17-rated, or unrated.

Theatrical trailers must be less than two minutes and 30 seconds, as mandated by the MPAA (Motion Picture Association of America). The MPAA gives each movie studio one exception to this a year where they are allowed to show a trailer that is longer than 2 minutes and 30 seconds. Trailers shown online can be any length. The rating system itself is entirely voluntary on the part of studios. However, having a film rated tends to boost revenues significantly, so nearly all major studios submit all their films for rating.