为什么我使用以下代码获得未捕获的类型错误？

The purpose of this code is to have 3 divs that change color when clicked and when the two colors in divs on the left make up the one on the right the user receives a positive message either on the console or the DOM. I thought I had this entirely figured out but now whenever I click a div I get an uncaught type error that says The purpose of this code is to have 3 divs that