The elemental bloodline's bloodline arcana feature grants the sorcerer the ability to change the energy damage a spell deals from its "base" energy damage to the energy type of their bloodline (cold, for instance):
Whenever you cast a spell that deals energy damage, you can change the type of damage to match the type of your bloodline. This also changes the spell’s type to match the type of your bloodline.
The feat Rime Spell states:
The frost of your cold spell clings to the target, impeding it for a short time. A rime spell causes creatures that takes cold damage from the spell to become entangled for a number of rounds equal to the original level of the spell.
This feat only affects spells with the cold descriptor.
What does "spell type" mean in the bloodline arcana, and can I use it to change, say, Fireball to a coldball and use Rime Spell to entangle the enemies damaged?
Related questions, but not addressing the issue of the descriptor changing or not with this bloodline arcana: spells still get their effects, which spells qualify for damage change. Searching "sorcerer elemental bloodline rime spell pathfinder" on this site had no results.