In the 2004 film, The Village, the villagers wear yellow as a "safe" color to protect themselves against the creatures that live in the woods beyond the borders of their village. The color yellow is to show the creatures that the villagers mean them no harm and that peace is to be maintained between them.
Ivy Walker (who is blind) needs to breach the borders and go into the woods. It is revealed to her by her father that the creatures actually do not exist, but they were simply used as a scare tactic to prevent the villagers from venturing into the woods and going to "the towns."
Ivy still wears her yellow cloak. She falls into a hole and gets her yellow cloak covered with mud. Realizing that something is following her, she gets extremely nervous and frantically tries to wipe the mud off of her cloak to reveal that she is wearing yellow.
If Ivy knew that the creatures were not real, why was she trying to reveal the color of her cloak?