Create an original icon

As a preparation, first create an original icon and save it in any folder. You can also change the background color, so we recommend saving in a transparent png format.

Change sub tool icon

Right-click the sub tool you want to change on the Sub Rule palette and select "Sub Tool Settings".

 

Click "Customize" of the tool icon and select the original icon created earlier. The background color can also be changed to any color.

Confirm that the tool icon has been changed to the original icon and select "OK".

I was able to change.