Kasina LEDs - why RGB and not RYB?

I'm curious why the Kasina LEDs are 2 Primary colours (Red & Blue) and a secondary colour Green, and not the 3 primary colours (Red Yellow Blue)?
Also, is there a colour wheel/chart specifically for programming the Kasina?
Thank you for any replies,
Peter.

Red, Yellow Blue are the primary PAINT colors. Red, Green Blue are the primary LIGHT colors. :-)
https://science.howstuffworks.com/primary-colors.htm

There are color wheel/charts everywhere!
Here's one: https://www.rapidtables.com/web/color/RGB_Color.html

Enjoy!

Thanks Andy, appreciate your reply. So much to learn ...