Overview
Skjǫldrinn is the original military order that goes back to 748 CE. It's been alternatively under control of Úlfhéðnar from three Norwegian royal blood lines, namely Sverreættin (Sverreætten in modern Norwegian, House of Sverre in English), Harðráðiættin (Hardrådeætta in Norwegian, Hardrada Dynasty in English), and Hárfagriættin (Hårfagreætta in modern Norwegian, and Fairhair Dynasty in English), as well as one Danish royal blood line, namely Knýtlinga (House of Cnut in English).
It is currently under the control of the heir of Sverreætten, Áskunnr hinn gullúlfr Bjǫrnsson (also unofficially known as Hákon VI), and soon his son(s), with this royal house more recently being referred to as Áskunnrættin (House of Áskunnr).
Next in line is Harðráðiættin, Knýtlinga, and Hárfagriættin. All by consensus (secured through a lot of fighting and subsequent treaty).
Whoever controls Skjǫldrinn, controls everything else. As it is Áskunnr currently, his blood line war banner is therefore everywhere. It is also the Áskunnr war banner that represents Norðsherstjórn (NHS) or Northern Troops Command currently.
Norðsherstjórn (NHS) is in command of Jómsvíkingar (JK), which is the contracting operation and main troops. Also for Væringjar (VG), which is the Varangian Guard and the Tier One group within Jómsvíkingar. Finally, Ásjárstjórn (AS), or Protection Command, which is like the security/police division (we jokingly refer to it as the Stasi). Note that everything has a specific color.
There is also Áskunnr & Brœðr, the more mainstream outfitting operations, not listed as kept separately for many reasons. Traditionally, trading and commercial operations not related to martial stuff have used a blue banner. This is still the case.
Colors
Patches and Flags
Yellow/Gold on Red/Blood: King and his oathed partner (rarely used on patches)
White on Grey: Skjǫldrinn
White on Burgundy/Blood: Jómsvíkingar (JK)
White on Black or Black: Væringjar (VG)
White on Khaki/Coyote: Ásjárstjórn (AS)
White on Blue: Ulf(S)
Official documents and correspondence
Yellow/Gold: King and his oathed partner (rarely used on patches)
Grey: Skjǫldrinn
Burgundy/Blood: Norðsherstjórn (NHS)
Burgundy/Blood: Jómsvíkingar (JK)
Black: Væringjar (VG)
Khaki/Coyote: Ásjárstjórn (AS)White
Blue: Áskunnr & Brœðr (Commercial/Trading/School of Combat)
Note that the name of each division/section is often replaced with "ÁSKUNNR" across the board (instead of Jómsvíkingar, Væringjar etc...) The division/section is therefore identified primarily by color.