how is colour used in films?

 in films colour is used to often get a message across or the feeling of a scene. this can also help show the characteristics and personality of a character 

red is used to show a romantic feel of the scene to the audience or a scene with high tentiton for example it could be used in a scene of confrontation before a violent scene plays out it can also be used to danger is near in a scene 

blue can be used to show isolation, sadness, loneliness and calm 

green is can be used to show evil, nature, ominus and pretty much all scenes shot outside