Circular Color Swatches in the WooCommerce Color Filter (CSS)

Drop the next CSS code into the plugin settings page -> tab Options -> “Custom CSS code“:

.woof_color_term{
   border-radius: 80px !important;
}

.woof_color_term:hover{
    border-color: #444;
    border-style: dotted;
}

Size of color boxes can be adjusted by:

.woof_color_term{
    width: 26px !important;
    height: 26px !important;
}