Access the editor by pressing the Pen icon on the upper right corner of the main script panel.
This will open the active palette in a seperate window, the Editor. Here you can rearrange, add, change and remove swatches.
simply click-and-drag a swatch in the Editor left / right in order to change its position in the palette.
Underneath the palette you will find multiple sort options. Each one will use a different sorting algorithm. Feel free to play around and see which one works best for you. Don't worry, changes only apply once you hit the "Apply" button.
Add, Edit, Remove, Share
Click "Add Swatch" from the sidebar menu to add a new Swatch. Colors will automatically add a new color to the palette. That color is actually generated to be harmonious relative to the color next to it.
Click a swatch once in order to open the color picker. From there you can choose a different color. Once you close the color picker dialog, the palette in the editor will change.
Above each swatch you will find a small "X" button. Pressing it will remove that swatch from the palette.
From the sidebar, click "Share" to open a new dialog, which will let you share the existing palette in the following formats:
RGB Normalized: 0-1
HSL Normalized: 0-1