In the dark, red light shines on red apples, Huang Xiangjiao and white plates. What color are they?

I don't know how many people have asked this question, and it has also been discussed at the national forum for primary and secondary school teachers. It involves not only whether yellow light is monochromatic; Others say that three primary colors are only the principle of color TV; Even some people use the "group theory" and "atomic spectrum" only in graduate courses to explain, and the results are inconclusive. As an old engineer majoring in engineering physics, I think it is very funny. Have scholars, teachers and students completely lost their basic scientific thinking? Physics itself is an experimental science, so such a simple experimental problem needs to be discussed and debated? This experiment is very simple, any family can do it: use the most common flashlight, find a red plastic bag to fold several layers on the flashlight, and hide in the bathroom at night to take a look at bananas or pears. If you are not at ease, you can also use a red laser pen (available in stationery stores) to illuminate and see the results. I have done it myself with my own children, and the result is of course "red light shines on yellow objects and appears red"! It's just a little light. I am well aware that this is a joke made by pseudo-scholars who compile textbooks, but I am surprised that no one has found such a simple question a mistake. No teacher has taken students to do experiments? Don't all teachers nowadays have no brains except reading from the book?