

Sure. Colors are a huge topic and I’m not a physicist. There are a lot of colorsystems, and I probably don’t know half of it, but I try to break it down.
There is no real “normal” colormodel. We just sort colors on a chart that fits our needs the best.
The color model you will see most often is, for instance, in Photoshop the HSV model. (Hue, saturation, value). It’s good but has its own flaws with the color brightness.

In Ittens and Munsells case, you can see a small difference in the colors that are opposite of each other, in both colorwheels. In munsels case, yellow is opposed to indigo. In ittens case yellow is opposed to violet.
itten

Munsell

That’s a small but significant difference. Opposing colors should combine into grey and not into other colors. In ittens case they don’t.
(Upper is correct, lower is Itten)
Munsell is closer to a perceptive color space that takes into consideration that colors have different value and chroma levels, and vivid yellow is brighter than a vivid indigo.

Itten only used the flat ring model and lost the value and brightness of colors.
Now I compare those two because they are from the same time period, and Ittens model even came a little later.
Munsells color model even holds today.




Glad I could help.
That is true, and I get that it should be simple for children. But that doesn’t mean that the foundation has to be incorrect.
Just using the simplified version of a correct layout like I showed you should be the way to go in this case.
Of course, most people won’t need to know what’s colorsystems there are. Itten is none of the less still teached by artschools even though it is this incorrect simplified version of a color space. At that advanced stage, there is no need to stick to a simplified version, let alone a one that doesn’t lead to correct results.
Ittens model is just a remnant of its time. And it keeps being shared because of that simplification. But hey, that how history sometimes goes.