Dalek hierarchy

Due to their highly militaristic culture, the Daleks operatee under what is nominally a rigid hierarchy; there are often variations to it, however, depending on era and circumstance.

Overview

Command structure

Figurehead

Dalek Emperor - the overall leader of the Dalek Empire.
Davros: Davros, the creator of the Daleks served as leader of the Imperial Daleks.
The Mentor: The creator of a faction of Daleks from another universe, who led them.

Council

Cult of Skaro: A council of elite Daleks created to think of imaginative strategies, previous to or during the Last Great Time War (DW: Doomsday onwards)
Dalek Council - a governing body under the Emperor. (REF: Doctor Who: Aliens and Enemies) In some instances, they appear to rule the Daleks in the permanent or temporary absence of an Emperor. (DW: The Daleks, Planet of the Daleks)

Commanders

Dalek Supreme - high-ranking generals, commanding major operations or planetary occupations. These are usually black. In the early days of the Daleks, the Supreme was the direct second-in-command to the Emperor. (The Dalek Chronicles) During the Imperial-Renegade Dalek Civil War, the Renegade Dalek faction was led by a Supreme instead of an Emperor; and in the New Dalek Empire, a red Supreme took command. (DW: Remembrance of the Daleks, The Stolen Earth)
Dalek Supreme Controller - red-coloured Daleks, second to the Supreme. (BFDE: "Death to the Daleks!")
Dalek Scientific Division - high-ranking, their needs override all other orders and concerns. (BFA: Return of the Daleks)
Dalek Saucer Commander
Blue Dalek - equivalent of non-commissioned officers (EDA: War of the Daleks)

Ordinary Daleks

Standard Dalek

Others

Special Weapons Dalek - designed solely for combat, lacking the abilities of the standard Dalek. Reviled as "the Abomination". (DW: Remembrance of the Daleks, DWM: Emperor of the Daleks)
Marsh Dalek - designed solely for swamp combat. (The Dalek Book)
Robomen - Cybernetically controlled slaves. (DW: The Dalek Invasion of Earth, BFA: The Mutant Phase)
Pig slaves: (DW: Daleks in Manhattan/Evolution of the Daleks)
Mercenaries - human, Werelox and Ogron soldiers have been hired

Visual distinctions

Daleks often showed their rank via colours. In one version, gold Daleks are the highest, followed by black, red, blue and grey. (EDA: War of the Daleks)

For a time, the majority of Daleks were silvery with blue "bumps", with Saucer Commanders being partially black and Black Daleks/Dalek Supremes being full commanders. (DW: The Daleks, The Dalek Invasion of Earth)

During the Last Great Time War and in New Dalek Empire, almost the entirety of Daleks shown were of the same colour; the Dalek Supreme in the latter was marked out by being red, while Dalek Sec of the Cult of Skaro was black.

Variations of standard colours have also included white (Imperial Daleks) and gold-bronze (Time War).