Order Swatch Colors By..
The 'Order Swatch Colors By' menu-item has three sub-menu items, enabling you to order the current Swatch colors by Hue, Saturation, or Brightness. Doing so will mark the Swatch as 'Altered', as indicated by the color of the 'Comment' label changing to red. You will then need to save the Swatch if you wish to retain the new color-order.