AN: I fucked up her age somewhat and I'm sorry, I wasn't sure how to incorporate what happened with how old she was. Also, disclaimer.
When Annabeth is 7 years old, she meets Thalia Grace. Thalia's hair is as black as the nighttime sky.
When Annabeth is 12 years old, she meets Percy Jackson. Percy's hair is as black as the bottom of the ocean.
When Annabeth is 12 years old, Thalia comes back to life and it's thanks to Percy and Luke. Her hair is black like a raging storm.
When Annabeth is 13 years old, she meets Bianca and Nico di Angelo. Bianca's and Nico's hair are as black as death.
When Annabeth is 13 years old, Bianca dies and she doesn't see it happen, just hears about how she'd taken something and paid the price. She took something for her beloved brother and saved Percy, more like.
When Annabeth is 13 years old, she sees the moment in Nico's life that he decides to be on his own. If he can't be with his sister, he won't be there. His hair is black like a bruise that really really hurt.
When Annabeth is 13 years old, she sees Percy holding the sky like she had not that long before. His hair is black like the universe above his head.
When Annabeth is 13 years old, she witnesses Thalia becoming a hunter of Artemis. Her hair is black like mud.
When Annabeth is 14 years old, she kisses Percy on the lips and watches as he... what? Kills himself to help Hephaestus? Hurts himself so badly, he goes missing just to be healed? She's not sure how to explain it. His hair is black like the ash that settles over everything in the vicinity, from the "eruption."
When Annabeth is 15 years old, she and Percy fight for the camp. His hair is black like the hell-hound's fur.
When Annabeth is 16 years old, she watches as the world falls down around them. She sees Nico and Thalia fighting alongside Hades and Artemis, for the few moments she looks down upon the battle, and she notices that their hair is as black as leather, tough and lasting.
When Annabeth is 16 years old, she sees Percy react to Luke being the hero - to Luke being what he never was to Percy and was to her and Thalia. His hair was black like a gun.
When Annabeth is 16 years old, Percy goes missing.
When Annabeth is 16 years old, she meets Jason Grace. Jason's hair is blonde like the sun.
When Annabeth is 16 years old, she learns of a Roman camp that Percy might be at.
When Annabeth is 16 years old, she watches Jason, Leo and Piper go into overdrive, trying to finish the Argo to get to the Roman camp.
When Annabeth is 17 years old, she meets Hazel Levesque. Hazel's hair is brunette like a bookshelf, but gold like a ring.
When Annabeth is 17 years old, she reunites with Percy, his hair black like the color associated with pain.
When Annabeth is 17 years old, she and Percy fall into Tartarus with nothing more than the clothes on their backs and Riptide. Percy's hair is black like the shadows cast around them.
When Annabeth is 17 years old, she, Percy, Hazel, Jason, Leo, Piper and Frank all save Camp Half-Blood, along with Reyna and Nico. They finally look happy.