In the Blood Runs Deep quest guide it states:

Under Daggermouth War #24:

 

Below are the various colours she'll turn and the corresponding attacks you should use:

 

* Grey: Any attack style

* Orange: Melee attacks only (Balmung)

* Green: Ranged attacks only

* White: Air elemental spells only

* Blue: Water elemental spells only

* Brown: Earth elemental spells only

* Red: Fire elemental spells only

 

She STARTS off as grey and you CANNOT do ANY damage until you attack her with the Balmung FIRST. She starts off with a Melee attack as well. You will not get 'grey' as a color in the cycle after you begin the fight correctly.

 

Thanks!

Vhellcat

Thanks so much for this information. We've edited the guide after going through the final fight again, it seems you're right!

 

You've been credited for the changes, PM me with any questions or concerns.