Prussian blue

Prussian blue was a dark shade of blue.

The Eighth Doctor wore a double-breasted overcoat of Prussian blue moleskin round the Kotturuh crisis. (AUDIO: He Kills Me, He Kills Me Not, Mutually Assured Destruction; PROSE: All Flesh is Grass)

Rose Tyler wore a Prussian blue hoodie when she helped the Doctor's eighth and eleventh incarnations deal with a parallel self, D'Pau, and some Sontarans. (COMIC: Empire of the Wolf)

Tegan Jovanka wore Prussian blue trousers during the Master's Dalek Plan. (TV: The Power of the Doctor)