We see Hilary Duff at the 'A Cinderella Story' Hollywood Premiere in 2004.
She is wearing very long, straight hair. No doubt hair extensions have been applied to achieve this desired look. The extensions are worked into her hair to intermingle with the angled sides along her face.
You can have long, straight hair extensions applied in any color for contrast and fun. Although the service is pricey, the long-term results make it worth it.