Lovely video, typically what the net has as information, unfortunately this is not 'color theory'. Modeern color theory begins with Newton, is restructured by Goethe, and finds some useful assistance with Edwin Land (Mr. Polaroid). Yet, unfortunately, as we like to say in good old Texas, "That dog don't hunt."
So, color theory, in the practical world what is the answer? "Red Cadillacs by GM". It works, is practical and you don't need anything else.
In a nut shell, Red Cadillacs by GM, reads Red and Cyan, then Blue Yellow, and finally Green Magenta. The other part is the black and white, (there is no gray) we call this neutral density. Back to a fine point, Cyan is equal amounts of Green and Blue, while Red is equal amounts of Magenta and Yellow.
Here is a rather interesting leap, because two lesser colors combine to make Red and/or Cyan, then there can truly only be two colors, they are Red and Cyan.
Why then do people have such trouble with color? Because they are confused by Cyan. Cyan is not Blue. Cyan is Cyan because EQUAL AMOUNTS of Blue and Green make Cyan. Cyan is NOT Blue, Blue is half of Cyan.
The astounding part of this is that you play in Photoshop (or one of its variations). But open these programs and you will see the colors in relation to each other. Look harder and you will see that Red and Cyan have the other four in them.
Final step in understanding Color theory, If these two colors, Cyan and Red make up all color, what can you say if you are not to speak the names of the two colors Cyan and Red? Simply that ALL color can be reduced to cool and warm sensations! Red is warm and Cyan is cool. When you bring the two together you get balance or neutral density.
Now that is a color theory that is basic, simple and that you can do in your head at any time.