A simplified version would be, I have a bitmap with three colours on it, I want to import that and then create three fill layers in Painter. I want to then sample my imported image somehow (using an eyedropper to store a value in a swatch) getting all three colours and applying them to the three layers base colour
EDIT: Think I figured it out, you have to click and hold the eyedropper. Unfortuntely the thumbnail's still a bit on the small side but this is workable