According to Patti Bellantoni , colors are used symbolically throughout the film , none more so than red , which is an important thematic signature that drives the story and " [ defines ] Lester 's arc " . First seen in drab colors that reflect his passivity , Lester surrounds himself with red as he regains his individuality . The American Beauty rose is repeatedly used as symbol ; when Lester fantasizes about Angela , she is usually naked and surrounded by rose petals . In these scenes , the rose symbolizes Lester 's desire for her . When associated with Carolyn , the rose represents a " façade for suburban success " . Roses are included in almost every shot inside the Burnhams ' home , where they signify " a mask covering a bleak , unbeautiful reality " . Carolyn feels that " as long as there can be roses , all is well " . She cuts the roses and puts them in vases , where they adorn her " meretricious vision of what makes for beauty " and begin to die . The roses in the vase in the Angela – Lester seduction scene symbolize Lester 's previous life and Carolyn ; the camera pushes in as Lester and Angela get closer , finally taking the roses — and thus Carolyn — out of the shot . Lester 's epiphany at the end of the film is expressed by rain and the use of red , building to a crescendo that is a deliberate contrast to the release Lester feels . The constant use of red " lulls [ the audience ] subliminally " into becoming used to it ; consequently , it leaves the audience unprepared when Lester is shot and his blood spatters on the wall .