Thelka

Thelka was a planet that was believed to be uninhabited.

History
In the year 2495, Thelka was colonised by humans due to the influence of an Aranjia advance party. The Aranjia arrived through a wormhole and eradicated the colour blue, even from the sky, until the Doctor and Amy Pond's intervention. (DWA: Blue Skies Thinking)