It's always been the standard abstract that I've heard to teach around it. In Ireland/UK it's something that gets brought up in primary and secondary schools,

It's always been the standard abstract that I've heard to teach around it. In Ireland/UK it's something that gets brought up in primary and secondary schools, first when talking about rainbows and then later in discussions on optics/refraction — e.g. you'd get kids to make their own Newton's disc (https://en.wikipedia.org/wiki/Newton_disc https://en.wikipedia.org/wiki/Newton_disc) and see colours blending together to white.