She becomes a genin when she's a young teen, bright and innocent to the ways of the world.
Her world is light and carefree, all in shades of white. All is right--she's in love, she's on the same team as him, and one day she's certain he'll love her in return and whisk her away to marry him, just like in those fairy-tales.
So her world is bright and happy and good, and she's content.
By the time she becomes a chunnin this changes. She's a teenager, and sees the world as an adult, knowing what tricks it can pull.
Her world is in disarray, drab and burdened with worry, and she sees in shades of black. Sasuke betrayed Konoha, is training with a man who may or may not be gay, and she's not sure she'll ever get him back.
So her world is dark and despairing, and the day she realizes she doesn't love him anymore may have been the darkest one of all.
And then she's a jounin, and she finally sees the world in color, because she's in love again, and it's not unrequited, and all is right even if she's not innocent anymore, but a pair of blue eyes and golden hair followed by the scent of cosmos will always be there for her, as she always has been, it's just that she's never noticed.
And so her world is as it should be, and it's because of a pair of blue eyes and golden hair followed with the scent of the cosmos.