Certainly is.
Add the following to the Text object (might work on other objects too, haven't tried it.) that you want to flash:
OnAutoAttackEffector="AutoAttackEffector" OnRangedAutoAttackEffector="RangedAutoAttackEffector"
And add the following above that object on the same page:
Code:
<EffectorCycleColor ColorEndUseCurrent="true" ColorOneUseCurrent="true" ColorTwo="#FD8002" MaxSpeed="5.000" MinSpeed="5.000" Name="RangedAutoAttackEffector"/>
<EffectorCycleColor ColorEndUseCurrent="true" ColorOneUseCurrent="true" ColorTwo="#FF0000" MaxSpeed="5.000" MinSpeed="5.000" Name="AutoAttackEffector"/>