This feature lets you edit the coat of arms used for your titles, dynasty, and house in-game and from within the ruler designer to create your own stunning medieval crest, and not much further explanation is needed, to be honest.
The meat of the system comes in the form of customizing your coat of arms from scratch or adjusting the existing one, both share their core components but the adjusted mode is more limited if you want to take a pre-existing coat of arms and just tweak it a bit.
The reason adjusted mode is separate is that some historical coats of arms are made up of a lot of emblems in an order that whilst looks pretty in-game is rather cursed if you were to try and see the full layout and background usage.
Starting with the background panel you can pick from any of the background patterns as well as pick what colours should be used. For all the colouring options in the coat of arms, designer Paradox have provided a palette with some pre-selected colours that are used in heraldry generally and are what they use in randomization of the coat of arms but we are also given a colour picker to let us pick whatever horrifying neon colour we want.
In the adjusted mode you cannot pick a background pattern but you can change the colours.
The bulk of time you will spend is likely to be in the final emblems panel, this lets you pick which of the over a thousand emblem textures that you want to use as well as how you colour them.
There is also a detailed edit mode that lets you go deeper and modify the exact positions, scale, and rotation of all your emblems as well as modify what layer they are on and even add and remove them to your heart’s content.
The UI of this mode is especially work in progress, especially the layering part of it, that will be tidied up before the release.