Solution:

1) If the Database window is not activated, activate the Database window.
2) Click the 'Forms' tab in the Database window.
Forms tab
3) Select the desired form to change. (The form is highlighted.)
4) Click 'Design'. (The form opens in Design view.)
5) Select the control to change. (Handles appear around the control.)
6) Select the 'View' menu and select 'Properties'. (The property sheet for the selected control appears.)
Property Sheet
7) Click the 'Format' tab from the Property Sheet.
NOTE: The controls' borders may vary, and some are not applicable in all cases.
8) To change the control's border width:

a) Click in the 'Border Width' property box. (An drop-down arrow appears.)
NOTE: Use the scroll bar if necessary.
b) Click the drop-down arrow button. (A submenu appears.)
c) Select the desired border width from the submenu.
Border Width
d) Click 'OK'.

9) To change the control's border style:

a) Click in the 'Border Style' property box. (An drop-down arrow appears.)
b) Click the drop-down arrow button. (A submenu appears.)
c) Select the desired border style from the submenu.
Border Style
d) Click 'OK'. (The border style of the control changes.)

10) To change the control's border color:

a) Click in the 'Border Color' property box. (The 'Build' button appears.)
Build Button
b) Click 'Build'. (The Color dialog box appears.)
Border Color
c) Select the desired color. (The color is highlighted.)
d) Click 'OK'.

11) To close the property sheet, click the 'X' button in the upper-right hand corner of the property sheet.
Click the X button to close property sheet
NOTE: The properties will be saved only when the design view is saved.
12) (Optional) To view the new borders of the control, select the 'View' menu and select 'Report'. (The report appears in Report view with the new control border changes.