Gold Dalek

Gold Daleks, also referred to as Golden Daleks, (PROSE: Day of the Daleks) were a high-ranking class of Daleks within the Dalek Empire prior to the Last Great Time War.

History
Gold Daleks were the highest-ranked Daleks within the Dalek hierarchy with the exception of the Dalek Emperor or the Dalek Prime, above Grey Daleks, Blue Daleks, Red Daleks and Black Daleks. (PROSE: War of the Daleks) In some cases, they acted in the place of Black Daleks as a Supreme Dalek. (TV: Day of the Daleks)

A Gold Dalek was in charge of the planet Earth in an alternate timeline where the Second World Peace Conference had failed and the Daleks invaded in the 22nd century in the aftermath of the devastating wars which followed. When the Third Doctor threatened to negate the timeline, the Gold Dalek led the Daleks and their Ogron servants back to the 20th century to ensure the Conference failed. They advanced into the Auderly House which was then destroyed by Sura using a Dalekanium bomb, taking them with it. (TV: Day of the Daleks) One account claims a Black Dalek was present as a second-in-command and was responsible for much of the Gold Dalek's tasks while the Gold Dalek acted as an overseer. (PROSE: Day of the Daleks)

On the eve of the Second Dalek War of the 26th century, a Gold Dalek led a platoon of Daleks to meet the Master on the Ogron homeworld. There, it ordered the Master's captives - including the Third Doctor, Jo Grant, General Williams and the Draconian Prince - exterminated. However, the Master convinced the Daleks to leave the prisoners under his supervision until the Daleks' planned war began, to which the Daleks agreed and left the planet. Later, the Doctor managed to escape the prison cell by using the Master's hypnosound device, which caused the Ogron on guard to perceive the Doctor as the Gold Dalek and he opened the cell out of fear. (TV: Frontier in Space)

Following the end of the Imperial-Renegade Dalek Civil War, Dalek forces were divided as some supported Davros while others supported the Dalek Prime. The Gold Daleks were the only rank that remained fully loyal to the Dalek Prime which gave him an advantage when a brief but destructive civil war broke out on Skaro. They were aware that their power would be diminished if Davros took over. (PROSE: War of the Daleks)

Other Gold Daleks
The Dalek Prime himself had a distinct gold casing. (PROSE: The Chase, War of the Daleks)

Following the Third Doctor's escape from the captivity of the Master and the Daleks, (TV: Frontier in Space) he had the Time Lords send him to Spiridon where the Daleks were in the process of waking up an army from under the ice. A black Dalek with a golden dome, solar panels and globes arrived on the planet and was said to be a member of the Supreme Council (TV: Planet of the Daleks)

By the end of the Second Dalek War, many Daleks had been given a sturdier bronze and gold casing and Dalek X, the Dalek Inquisitor General, had a black casing with golden globes and solar panels. (PROSE: Prisoner of the Daleks)

Davros's Imperial Daleks had white casings decorated with gold, including their globes, indicator lights, gunsticks, manipulator arms, neck casings and eyestalks. (TV: Revelation of the Daleks, Remembrance of the Daleks)

During the Last Great Time War, the bronze and gold casing from the Second Dalek War became standard for Dalek drones (TV: Dalek, The Last Day, The Day of the Doctor) and a similar look was used for the Emperor. (TV: The Parting of the Ways) These casings were eventually used again for the foot soldiers of the New Dalek Paradigm. (TV: Asylum of the Daleks, The Time of the Doctor, COMIC: The Dalek Project, PROSE: The Dalek Generation)

The red Supreme Dalek of the New Dalek Empire had golden globes and extra gold casing. (TV: The Stolen Earth/Journey's End)

Behind the Scenes

 * According to the non-narrative material in The Dalek Handbook, the civil war between the Dalek Emperor's guards and the Humanised Daleks (TV: The Evil of the Daleks) ended in a victory for the Emperor's forces. Afterwards, the Emperor revamped the Dalek command structure, which involved replacing Black Supreme Daleks with Gold Supreme Daleks.
 * The Eternal Dalek of the New Dalek Paradigm introduced in TV: Victory of the Daleks has a similar colour-scheme to the Gold Daleks since both have black globes. However, the Eternal Dalek has a solid yellow casing instead of gold.
 * Nicholas Briggs voices the Gold Dalek (and the other Daleks) in the Day of the Daleks Special Edition DVD.
 * A Gold Dalek, alongside a Black Dalek and a Red Dalek, leads the 22nd century Dalek invasion in Daleks' Invasion Earth 2150 A.D., a non-canon retelling of The Dalek Invasion of Earth starring Peter Cushing.