I'm not 100% I understand what you're getting at, but it sounds like the instance you're creating is spawned after dragging and dropping one of these colored objects, is that right?
I'm assuming you would need to toggle the type of object you're wishing to create (I'm conceptualizing a tower defense style thing here). If that's the case, maybe you can have a variable that changes to the name of whatever object needs to be spawned when you select it. Then, when the colored object is released, it spawns the object with the name of that variable and is destroyed.
Again, let me know if that's way off base.