Elemental Preference

Through your knowledge of spellcasting, you’ve developed the skills necessary to change the damage type of your spells. 

• You can change the damage of any elemental spell that deals the following damage types: thunder, lightning, fire, cold, acid into different type in the same list. This must be done before casting the spell.
•  The spell must only deal that type of damage. Example: Fireball's damage type can be changed, but Meteor Storm's cannot as it also deals bludgeoning damage in addition to fire. 
•  Any effects caused by the original damage type of the spell no longer take affect. Example: if Fireball's damage is changed from fire, the spell no longer ignites objects in it's blast zone