The red dragon bloodline boosts fire spells.
If you change the element to a different one, it is no longer a fire spell.
QED.
elemental spell doesn't say it changes the descriptor which is what draconic relies on. It's a fire descriptor spell that is doing acid damage.
Chess Pwn is correct.
Though I don't recall any substantial evidence supporting the stance, I've heard it said in plenty of places on and off these boards that that changing the energy type WOULD change the descriptors of the spell, thus disqualifying this combo.
Bloodline Arcana: Whenever you cast a spell with an energy descriptor that matches your draconic bloodline's energy type, that spell deals +1 point of damage per die rolled.
Added quote
Elemental Spell (Metamagic)
Benefit: Choose one energy type: acid, cold, electricity, or fire. You may replace a spell's normal damage with that energy type or split the spell's damage, so that half is of that energy type and half is of its normal type.
Either you can use Elemental Spell (fire) to change a Cone of Cold to fire and get your extra damage (because the descriptor changes), or you can use Elemental Spell (cold) to change your Fireballs to cold and not lose it (because it didn't). The way that the feat is worded, it's the second. This may be intentional, because it severely limits the application of Rime Spell metamagic, which requires matching cold descriptor & damage. However, it's not very intuitive.
So I'd check with my GM if I were you.
Though I don't recall any substantial evidence supporting the stance, I've heard it said in plenty of places on and off these boards that that changing the energy type WOULD change the descriptors of the spell, thus disqualifying this combo.
+1 on this a fire spell doing acid damage makeseven less sense than magic normally does.
Elemental spell does not say that it changes the descriptor of the spell. So the ice fireball still has the fire descriptor and still benefits from the bloodline. The fire shocking grasp doesn't gain the fire descriptor so even though it is doing fire damage, it doesn't gain the descriptor, so no benefit from the bloodline.
Of course one could argue that the elemental spell *does* change the descriptor, which leads to people combining this with Rime spell to entangle people with an Elemental (cold) Rime fireball. Or the Elemental (cold) Rime magic missile.
+1 on this a fire spell doing acid damage makeseven less sense than magic normally does.
Oh, I agree, but for comparison purposes, this is the Efreeti bloodline arcana (with my bolding)...
Efreeti... Bloodline Arcana: Whenever you cast a spell that deals energy damage, you can change the type of damage to fire. This also changes the spell's descriptors to match this energy type.
I'd think that if they wanted Elemental Spell (cold) to permit a combo with Rime Spell, they'd have FAQ'd the first around the time they wrote UM and grappled with the whole damage/descriptor issue.