(Cover) - EN Star Style - Ryan Reynolds has nicknamed Blake Lively's new hair colour.

Blake died her signature blonde tresses red in April for her role in comedy drama Hick. Although she's headed back to her light locks, Blake's locks are still in the transitional stages, and are currently a mixture of red and blonde.

The stunning star, 23, says her Green Lantern co-star Ryan has taken it upon himself to name her unusual hair hue.

"Ryan named my hair colour sierra sunset,' which I like," she told People magazine at the film's Los Angeles premiere on Wednesday night.

In science fiction action film Green Lantern, Blake plays Carol Ferris, and she sported brunette locks for the role. The actress enjoys experimenting with varying hair shades for her film parts.

"Having brown hair for this movie was so much fun," she said. "When I play a character I love to completely transform. That's the only way I feel like I can disappear behind them." (C) Cover Media