Affinity Designer can use different colour models to represent different ways of describing colour. A model (RGB, CMYK, LAB, or Grey) can be selected as you create your new document.
Colour definitions are described comprehensively on the internet, so in this chapter we'll just focus on how to set a colour model, the model's colour space, and how a colour profile represents that colour space.
In terms of selecting colour as you design, Affinity Designer offers the Colour panel, which shows the HSL colour wheel by default but offers RGB, CMYK, HSL or LAB sliders instead. Within the panel, a Swatches section offers easy access to preset swatches for single-tap application.
If you're happy to leave colour management until output is required, you can create new documents with the suggested default colour format RGB/8 with sRGB IEC61966-2.1 colour profile. However, for professional printing it's recommended to ensure a CMYK colour profile is adopted on document creation.