Something I found fascinating about this the second to last image here was how Grey Wolf's eyes were both completely yellow after she finished howling. While it might be, and probably is, just an error in design seeing as their back to yellow and blue in later comics, I like to think its symbolic of Grey Wolf's coming of age.
A wolf pup is born with completely blue eyes, which gradually turn to yellow, brown, green or even grey as they mature. Back when she was still just a wolf pup, Grey's eyes were both blue, signifying her immaturity. After the traumatic experience at the waterfall, her right eye turns yellow, symbolizing a step forwards in her life: she's gaining a sense of the real world through a realization of her own mortality and the sudden change in form. She remains like this, between immature and driven, not really wanting to fully embrace and grasp the finality and just wanting to revel in the new stimulation and experience carefreely, throughout her journey, the mindset being chipped away at by her sort of mentor figures, Pangolin and Northern White-Faced Owl, forcing her to reflect a little and even move forwards without their beckoning. This finally comes full circle when she finds her mother again and, realizing how much she's changed and how far she's come, howling at the moon with her mother to announce her coming of age, her left eye completing the transformation to yellow: in this moment and time, Grey Wolf has acknowledged her maturation, and is ready to move forwards.
Something I found fascinating about this the second to last image here was how Grey Wolf's eyes were both completely yellow after she finished howling. While it might be, and probably is, just an error in design seeing as their back to yellow and blue in later comics, I like to think its symbolic of Grey Wolf's coming of age.
A wolf pup is born with completely blue eyes, which gradually turn to yellow, brown, green or even grey as they mature. Back when she was still just a wolf pup, Grey's eyes were both blue, signifying her immaturity. After the traumatic experience at the waterfall, her right eye turns yellow, symbolizing a step forwards in her life: she's gaining a sense of the real world through a realization of her own mortality and the sudden change in form. She remains like this, between immature and driven, not really wanting to fully embrace and grasp the finality and just wanting to revel in the new stimulation and experience carefreely, throughout her journey, the mindset being chipped away at by her sort of mentor figures, Pangolin and Northern White-Faced Owl, forcing her to reflect a little and even move forwards without their beckoning. This finally comes full circle when she finds her mother again and, realizing how much she's changed and how far she's come, howling at the moon with her mother to announce her coming of age, her left eye completing the transformation to yellow: in this moment and time, Grey Wolf has acknowledged her maturation, and is ready to move forwards.
I don't think it's a design error, Grey Wolf's heterochromia is one of her defining features. Plus, two pages ago, it was still blue, and the previous page starts to show some green instead before turning yellow here. Your theory is pretty interesting in that sense! Her eyes turning back to blue doesn't mean it's an error because visibly she doesn't remember this time nor her bag and even the owls don't, meaning either she forgot or it's a different Grey Wolf, as when a Friend dies, she forgets her memories even if she is reborn with sandstar again (there were theories about Grey Wolf being there during the KemoFure game era then forgot because she either died or forgot with time until the time of the anime, since the legends she tells are ceruleans that existed). So maybe she was reborn after dying, it's a different Grey Wolf, or that she just forgot but then lost that maturity status. Something like that isn't totally impossible.