Add: click the dashed “+” chip at the end of the palette.
Edit: double-click a chip (or choose Edit from its context menu) to open the colour picker. Edits preview live—every pixel already painted with that colour updates as you adjust it—and commit as a single undo step when you close the picker.
Remove: choose Remove from the context menu. Colours in use on the canvas can’t be removed.
Reorder: drag chips (in Manual sort mode).
The chip context menu has shortcuts for building tonal ranges:
Gradient generation skips protected colours, so mark ramp endpoints as protected to keep them fixed.