Abstract:

The teaching of colours mixing is one of the activities carried out in all preschools and primary schools. There are many activities with colours and/or colours mixing that can be explored in the classroom. These activities provide the first contact of children with colour theory and can have an important role in the formation of scientific concepts. However, the generality of the activities fit into teaching by mixing the primary colours of paints (not always taught correctly) so as to get the secondary colours. The students begin to learn the basics of colour theory based mainly on the subtractive colour model, which can lead to several misconceptions concerning the concept of colour. Many of these misleading ideas about colour persist into adulthood and can be found even in university physics students. A very common misconception is that mixing the same colours using lights or pigments will give the same result. Therefore, it is important to develop appropriate learning activities which can allow students to explore additive colour mixing through the mixing of coloured lights as well as understand that the primary colours of light (red, blue and green) are different from the primary colours of pigments (cyan, magenta and yellow). These activities should also allow students to see that white light is actually made up of all of the colours of the rainbow and help them to understand how we perceive colour. In this work we start from the knowledge that the colour of an object is most often the result of absorption or subtraction of certain parts of the visible spectrum, through selective reflection or selective transmission of the remaining parts of the spectrum, to explore some illustrative and intuitive activities. These activities will allow students to explore white light decomposition, additive colour mixing and subtractive colour mixing (either using paints or coloured filters). Some of the proposed activities are based on the exploration of some recently published children’s books whose coloured images are created using a technique that revealed different images under different lights (RGB art) e.g.[1-6]. Each image is made by three different layers, each of them containing either a cyan, a magenta or a yellow image. Using a set of coloured filters (usually red, green and blue filters) that come with the books it is possible to see clearly the layers that compose the image. Students are invited to make draws using different colours and using coloured filters see how the draws change when illuminated by different colour lights. These activities will help students to understand that colour is not an intrinsic property of an object and it depends not only on the physical properties of the object but also on the characteristics of light that illuminates the object and on the human visual system. The work presented explores a script of activities designed to be used by teachers of preschool and primary education.

References:
[1] Demois, A., Godeau, V. (2015) The great journey. London: Tate Publishing.
[2] Bestard, A. (2015) What’s hidden in the woods?. New York: Thames & Hudson.
[3] Bestard, A. (2016) What’s hidden in the sea?. New York: Thames & Hudson.
[4] Bestard, A. (2017) What’s hidden in the body?. New York: Thames & Hudson.
[5] Carnovsky, Williams, R. (2016) Illuminature. London: Wide Eyed Editions.
[6] Carnovsky, Davies, K. (2018) Illuminatlas. London: Wide Eyed Editions.

Keywords:

Additive and subtractive colour mixing, primary and secondary colours, visible light spectrum, didactic activities, RGB art.