Well Nykos if your working with the code that I used we are both at the same point with this.
I honestly don't know how to do this type of game yet and am still trying lots of different ideas.
I too noticed the issue with the colourmatch++ not working from the start. There was also an issue with the new ball colliding in the middle of 2 balls of the same colour(not sure if I fixed this in that last upload)
What I'm struggling with is how to check all the balls out of sequence. I think a get all actors in collision is the way to go .
I'll try some more things over the next few days and post any positive results.
A few other points -
setup actor when used correctly will be used to place the balls in there correct locations too. Rather than having 100's of clones on screen that you may have to delete at some point. Planning levels on paper and using arrays will probably be the best option here. But this is not needed yet
checker actor : I think I got rid of in the latest build I'm working with so it's not too important.
The Ball Checker animation isn't quite right. It needs to be a bigger version of the ball so it can correctly identify which balls are in the collision. However I just made it quickly in paint and it's not the correct shape so it sometimes misses out collisions.
Your image appears to have the balls floating. For what I'm looking at any ball not attached to the top bar directly or through the colliding balls, will fall. If you do not need this feature then you can remove the top bar.