How to reset the Theme Style Kit
If you want to clear all the Styles from the existing theme Style Kit, you can easily reset it.
In the Elementor Theme Style editor, Navigate to the Theme Style Kit panel.
Click on the Reset button.
Once you do so, you will see a pop-up that will ask you to confirm.
This action will clean-up all the styling values from the UI controls. You can revert / undo this however by making use of the Actions and Revisions functions under History.