Steel blue

Steel blue was a shade of blue colour that resembled blue steel, i.e., steel which had been subjected to bluing for protection from rust.

Josie Day wears a double-breasted steel blue tailcoat without sleeves. (COMIC: A Matter of Life and Death, The Lost Dimension)

Rose Tyler wore steel blue denim overalls when she met Queen Victoria and a werewolf during the Wolf attack of 1879. (TV: Tooth and Claw) She also wore a cropped jacket of steel blue leather when she and the Tenth Doctor met the Wire. (TV: The Idiot's Lantern)

Jo Grant wore a steel blue denim pinafore when she first met Mark IV Daleks including a gold leader as well as their Controller and Ogrons during the Time Paradox Incident. (TV: Day of the Daleks)

Jenny Flint wore a steel blue cravat during the Battle of Demons Run. (TV: A Good Man Goes to War)

Jo Grant wore a steel blue jacket when she met the Bannerman Road Gang, the Eleventh Doctor, and renegade Shansheeth. (TV: Death of the Doctor)

Nyssa wore a steel blue mini-dress over an ivory underdress. (TV: Mawdryn Undead-Terminus)

Tegan Jovanka wore a double-breasted military jacket done in charcoal grey with a steel blue trim. (TV: The Power of the Doctor; WC: The Passenger)

Rosita Farisi wore a steel blue pinstripe petticoat when she helped the Tenth Doctor and Jackson Lake foil Cybus Cybermen during the 1851 Incident. (TV: The Next Doctor)

Professor Jericho and Dan Lewis wore alabaster and steel pinstripe shirts during the early 1900s, the 2021 Sontaran Invasion of Earth, and the Flux. (TV: Survivors of the Flux|The Vanquishers)

Janice wore steel blue denim jeans, which had a smiley face on their right leg. (GRAPHIC: Janice)

Shirley Anne Bingham wore a blazer of steel blue pinstripe when she witnessed the Toymaker’s defeat and the Fifteenth Doctor’s birth. (TV: The Giggle)

Many Sontarans wore steel blue space armour with navy helmets and pauldrons. (TV: The Sontaran Stratagem/The Poison Sky, The Last Sontaran, The End of Time, The Pandorica Opens, A Good Man Goes to War, The Crimson Horror, The Time of the Doctor; AUDIO: The Sontaran Ordeal, The Eternity Cage, The Great Sontaran War, The Sontaran Project; COMIC: Fugitive, When Worlds Collide, The Instruments of War, Supremacy of the Cybermen; GAME: The Gunpowder Plot, The Doctor and the Dalek)

Rona Bellows, a wheelchair-bound grandma, wore a steel blue scarf with alabaster symbols when when dreaming she was a scientist on the North Pole during Christmas Eve and able to walk because of dream crabs. (TV: Last Christmas)

Kate Stewart wore a steel blue shirt before and during the 2021 Sontaran invasion of Earth and the Flux. (TV: Survivors of the Flux|The Vanquishers)