In this study, a box, which we call a dark box, is made to keep out light and has a peephole for looking inside. Colorful remote-controlled RGB light-emitting diode (LED) lights and yellow, white, and blue plastic objects, shaped like cat masks, were inserted inside the box. We prove by several experiments using the dark box that light that appears yellow can consist of red and green light.

The Sun and ordinary lamps generally produce white light.1 White light contains red, orange, yellow, green, blue, and violet colors. Therefore, we see objects in different colors because these objects reflect one or more light colors from the rays that make up the white light and absorb the others.2 As a result, we see these objects as the primary light color or a color formed by a mixture of primary colors.3,4

In this study, the box was inspired by...

Supplementary Material

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