Karen Gillan is excited to be back in blue for Guardians of the Galaxy Vol. 2

It's not easy being green, said Kermit the Frog. But being blue is a blast, according to Guardians of the Galaxy star Karen Gillan.

As filming for Guardians of the Galaxy Vol. 2 got underway, the former Doctor Who companion posted a photograph of the blue, long-nailed fingers of her space pirate character Nebula. "It's good to be back in blue," she wrote.

Nebula, is "very much" appearing in the superhero sequel, confirmed director James Gunn in a live Q&A on his Facebook page earlier this month.

"It's exciting to have Karen Gillan around more," he continued, revealing that her role is "bigger" this time around.