thank you for your input and you are partly right, putting the balls further away will be the next step.
The target of the exercise in the video is also to raise Funnys awareness for colors. Just using the colored boxes might help her to get an idea more easily of not only which color matches but also which one does not. Ideally she should be aware of this before she takes the ball in her mouth.
In the video, Funny is offered most times a wrong option and a right one, and I think she does pretty well, because we have played this game not that often yet.
Nevertheless we tried your proposal today and I have thrown only on ball further away, but offered all three boxes. At first we tried it with yellow five or six times. Funny succeeded every time putting the ball in the yellow box, altought I swapped the position of the boxes every time (middle, left or right). That was a big surprise and made me really happy. But afterwards Funny did not do as well with blue or red.
That raises further questions as i am not a dog psycholgist:
How long is a dog able to remember the color of the ball after taking it in its mouth?
How long is the attantion span of a dog that makes it able to focus on this task at all?
Is red, blue and yellow ok, or can a dog differentiate another combination of colors more easily?
Thank you for your attention and please excuse my write errors