Affinity Designer 1.8.4 -

Windows users gained the ability to create application-wide color palettes.

It became possible to edit vector brush defaults before drawing on Windows. Affinity Designer 1.8.4

You can create them by checking the "create artboard" box when setting up a new document preset via File > New . Windows users gained the ability to create application-wide

Are you trying to find a within version 1.8.4, or Affinity Designer 1.8.4