Yes, wait 0 can be used to 'break up' events. Here is what I came up with, made few other changes to the project. Colors can be now set with single event, no matter how many you add. That should simplify things quite a bit.
I wasn't really sure what your final intention on picking and choosing colors for corners is, so I just set the to pick the color of closest circle.
Also notice how I used local variables 'blue' and 'purple' to keep things a bit cleaner. I never like to reference to a number inside code, rather into meaning of that number :)
Colored corners