Indigo (colour)

You may be looking for the plant or the Caxtarid named Indigo.

Indigo was a colour between violet and blue on the visible spectrum. (TV: Sky)

The Eighth Doctor wore an indigo cravat. (COMIC: Dreadnaught)

Rose Tyler wore an indigo leather jacket. (TV: Partners in Crime, Turn Left, The Stolen Earth, Journey's End)

Donna Noble wore an indigo blouse. (TV: Planet of the Ood)

Josie Day wore an indigo cravat with her steel blue tailcoat and her lavender blouse. (COMIC: The Lost Dimension)

Vortisaurs had indigo skin with stripes. (AUDIO: The Book of Kells)