Affinity Photo - Beginners Look At Colour Space
Affinity Photo - Beginners Look At Colour Space and Recolouring Black Text and Logos
PC-Mac Version - although relevant to iPad version also.
This tutorial looks at working with what can be called Colour Space or Colour Format or most likely the correct term is Colour Profile.
The tutorial is for beginners, who may be having trouble adding colour to an image they have acquired or some text they have typed. If the image or text is in the wrong colour space it will stop you adding any colour to the image, text or background.
I have also done a quick look at removing a white background from a black image.