She used to hate the color red.
It was the color of the clan symbol etched into her arm, laced with memories of burning and pain that no nine-year-old should have to endure. It was a permanent scar, a symbol of the past. Red, a color so highly regarded by her Oriental ancestors. Yet now, it was only a reminder that they were all gone, and she was the last one standing. Red was loneliness, a child with no true family left.
Sometimes, it was the color of her father's eyes, and then she'd hide her own onyx ones in the comfort of her mother's arms. Other times, it was the color of her mother's eyes after she'd been crying about things that Mikasa was too young to understand. She grew to realize that it was evidence of a cruel and dangerous world where safety didn't exist and protection was nothing more than a word. A world where everything ends in death all too sudden and far too soon.
It was also the color of blood. The bright crimson color that soaked corpses in the Survey Corps' carts, just barely within her line of sight. It even stained the cloaks of surviving members, a vivid reminder of death in the green garments of the living. It was her father and mother dying a thousand deaths before her eyes, a memory she wanted to forget but never could.
Red was the color of the Titans. It dripped grotesquely from their mouths and drenched their skin in far too many places. It evidenced their power over humanity. Red was powerlessness. Red was fear.
And yet, red is also warmth.
She considered this fact as she wrapped the scarf around her neck the same way she did every single day since that first time Eren had wrapped it around her. Bringing it up to cover her nose and mouth, she took a deep breath. It was amazing that, no matter how many times she washed it, Eren's scent remained faintly buried in the crimson folds of fabric.
Red is Eren, too, she decides. Eren, and his passion and violence and anger; fists too eager to fly, words always harsh to her gentle ears, heart ceaselessly devoted to a cause that may very well be the death of him. Red is the color of her hero, the one who saved her from a fate where pain and fear and death would have been imminent. Red represents humanity's hope.
And later, when Ian remarks that Eren is her boyfriend and her face turns a scarlet shade of red she didn't know was possible, she replies, "He's family", and realizes red has another meaning as well.
Love.
She wonders how she ever hated such a beautiful color.