Hi,
it's going to be easier if each cube has a picker drop fsm that listen to mouse hovering, and upon hovering, query a manager if it needs to change its color, then you can make a template out of this and add that to all your objects that needs to react on coloring hovering.
you could also simply use a global variable, and if the color is not 0,0,0,0 it gets applied.
Bye,
Jean