you'll need to create an attribute called beamColor and setup a rule on the button that when it's touched, change the value of beamColor to whatever you want.
then in the beam actor, create a few rules like this
if beamColor = 1 change image to blue if beamColor = 2 change image to red
something like that will work, but someone else may have a better idea
Comments
then in the beam actor, create a few rules like this
if beamColor = 1
change image to blue
if beamColor = 2
change image to red
something like that will work, but someone else may have a better idea