Abstract The implementation of practical activities that involve colors consists in a powerful strategy to stimulate the children and teenagers' interest in Science. Due to its strong visual appeal and presence in everyday life, colors spark students' curiosity and allow the learning of fundamental concepts in Optics, such as reflection, transmission and refraction. In this work, we describe a program of activities developed to teach concepts of Optics present in color formation by means of simple, cheap and accessible materials. Through open demonstrations and the students' autonomous discussion, we clarify the process of color formation by reflection and transmission, as well as the reason by which we can observe colorless objects. The ac...