Lily Evans, of course, is red. Deep red, like autumn, like cozy blankets, like a crackling fire. Everyone knows that Lily Evans is red. She is intense and she captures you, wraps you up, brings you home. She is the sunset the night before a storm—brilliant and fiery and alive.
Because Lily is red, she grabs you. She makes you notice her because her very existence screams for your attention. She doesn't ask for it, you simply simply given to her, because she is alive and you want to share in her life. She has an effervescence that draws you in. You want to become her in the same moment you understand with sudden, heartbreaking clarity that you could never be her.
Lily is red, and because she is red she drowns out the colors around her, without ever realizing. Usually, these colors can fight back—the bright forest green of James Potter does not even have to compete with her, because he fulfills another need. Lily jump-starts you to life; James dances on the edge of your consciousness, shaking you awake but bringing you to life just as strongly as Lily does. That is why they work so well together: nothing in the universe is as alive as the two of them.
But because nothing is as alive as Lily, except for James, who together and golden and bright and beautiful, other colors can be overlooked. A sunset is more vibrant, more alive than a sunrise, something that has never made sense to Petunia. The life in the world cannot exist without the sunrise, and yet the life in the world chooses with the last of its warmth to send the sun over the edge in screaming color.
Petunia Evans is the beach at sunrise: soft blue, quiet beige, patient grey. She does not scream, like Lily. She is not alive in the way that Lily is alive. Petunia breathes. Petunia is the quiet, dewy unfolding of flowers in the morning, not their brilliant show in the afternoon. Petunia is the rippling brook; Lily is the roaring waterfall. Petunia is nature's spring sigh, waking up after the long winter's sleep. Lily is the exhausted and exhilarated falling into slumber after a day spent outside in the sun, chasing adrenaline and adventure.
Lily, Petunia thinks, cannot exist without me coming first. I am the unfurling, the springing, the beginning. Petunia is the first breath; Lily is everything after. It is not fair, Petunia thinks, that Lily is adored for existing, when Lily could not exist without Petunia.
Petunia never understood that the sunset is the sunrise, on the other side of the world. Petunia never understood that she could not exist without Lily, just as Lily could not exist without her.
Opposites exist to attract: spring and fall, sunrise and sunset, open and close.
But perhaps Petunia never got a moment to listen to the enduring crash of the ocean over the siren song of adventure.