Most school science is oversimplification by design. It’s part of the learning process. Yo first learn colors, then when you are ready can learn about wavelengths, color spaces, biology of the eye, color psicology and many many other knowledge fields.

Even when you get into the anatomy of the eye you get “false” information, like the “perfect” cones that only percibe one color, or the misconception that every color is equal. More advanced education gives you more context and nuances.

In the taste and tongue case can be useful to explain that senses are the product of discrete sensors. That you don’t taste with your tongue but with specialized little taste buds. The different concentrations are mostly real, so the tongue map is a first step, even being so so far from the objetive and complex truth.

The problem is people that think they only need whatever high school education they got to be experts in pandemics, gender, biological sex, business, economics, history, politics and everything else.

Take note that I’m not only talking about a formal education. You can really learn a lot (most things? Maybe everything?) by yourself. But you have to be critical with your sources. You have to know how to learn. You have to understand how little you know about everything and how much you still have to learn.

Most “do your own research” people in the internet do not do actual research, don’t know how to do research and I don believe they know what research is.

I guess a combination of things. Bad early science that was easy to present in a little diagram. Then when it's disproved, nothing similar to replace it with but the unglamorous fact that it all just sort of tastes the same.