"Create Layer" Area

This option allows you to create a layer for the bubble effect.
- LastName:
Enter a name for the layer.
- Color:
Click on the color icon
to choose the color of your layer.
Once these options have been set .....
... your bubble effect will be automatically inserted into the specified layer.
In the drawing, the speech bubbles were indeed created on the layer created with the new color.
Later, if you want to create guides on an existing layer, you can always select it from the drop-down list.