Thank you for your response. I should have been more clear. I'm trying to create a memory match mini game and not a Match 3 game. I'm not an advanced user, so I wouldn't know where to begin on how to adapt the tutorial you linked to my needs. I appreciate the suggestion though.
Thank you for posting the screenshot. I'm a visual learner and it helps me a lot. Please bare with me, I'm an animator and I don't think like a programmer, but I'm trying to understand your logic. Let me know if I'm understanding you correctly.
So for the first event, for each placeholder object, if a coloredBalls family member isn't overlapping it, create a coloredBalls family member on it. That sounds really good.
In the second event, if the blueBall object is overlapping the placeholder object, set the global number blueBall to the number of instances of the blueBall object and if that number is greater than 2, pick a random blueBall instance and destroy it?
Seems to make sense to me, but I think I did something wrong, because when I run the layout, I'm not getting 2 of each colored ball. Sometimes I get 5 of the same colored ball and sometimes one color of a ball is completely missing. Will you be kind enough to take a look and tell me where I went wrong? I'm not seeing it.