Aquamarine

Aquamarine was a light shade of blue.

Rose Tyler wore an aquamarine hoodie during the Battle of Canary Wharf. (TV: Army of Ghosts/Doomsday)

The Third Doctor wore a smoking jacket of aquamarine velvet. (TV: Invasion of the Dinosaurs)

In the 20th century, the Torchwood Institute found a device which was aquamarine in colour. (PROSE: Slow Decay)