Porque é que as folhas mudam de cor no Outono?

Synopsis: This experiment allows students to discover why the leaves change color in the fall, through observation of practical activity that simulates the natural processes related to this phenomenon.
Source: Universidade Estadual Paulista (UNESP / Presidente Prudente) - Teacher Portal.
URL: http://ambiente.educacao.ba.gov.br/conteudos-digitais/conteudo/exibir/id/321