If you have an image from which you want to generate a palette, you can import the image into Colour Palette Editor and then create a palette from this.
If the current palette has changed, you will be prompted to save it, discard changes, or cancel the creation of the new palette.
Drag with the mouse to create a new selection. This only works if you drag outside the current selected, or if no selection is present.
Click inside the existing selection and drag with the mouse to move it
To clear the current selection, click in the preview control and press the Delete key.
If no selection is set, the entire image will be used.