The card screen movie rating system is somewhat similar to the MPAA ratings of the movies. They are, however, not absolutely identical. This is why sometimes the background of the rating announcement preceding the movie’s trailer may show a lighter or heavier warning than the MPAA one. While green backgrounds are usually behind every movie that is suitable for all audiences according to MPAA, there are occasions where the R-rated movies also have a grassy bg. This happens when the profanity and everything else that makes the movie unsuitable for minors has been edited out.
Red colour is behind R-rated, NC-17 and unrated movie trailers while yellow is usually internet-appropriate (whatever that means).