Movie Trailer Colors

There are three colors preceding each movie trailer, red, yellow, and green. These colors show up as the background for movie rating cards. The rating for the film itself shows up in text, but the rating for the preview shows up in text and indicated by the background color of the rating card splash screen. The specific regulations surrounding what can be shown in the preview for each of these rating cards are set by the Motion Picture Association of America (MPAA), though the rules are not publicly made available.
The most common 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 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.