Visual Composer plugin is provided with easy row and column editing and styling option directly from the editor panel. You can find the row and columns marked with a “Edit” symbol near each text as shown in image below.
Clicking on to the row edit icon will pop the “Row Setting” panel where you can enter the row styling options like the margin border, padding, background etc, which are applied for the entire row.
Also individual inner column page elements can also be style with margin, border, background, etc. by clicking the column edit option which will pop the modal box with the different styling boxes for the user to enter the values as shown below.