Open the form in Design view or Form view, or the report in Design view.
Make sure that the control is selected, and then on the Format menu, click Conditional Formatting.
Do one of the following:
To change an existing condition, select the font style, color, or other formatting that you want to apply.
To add a new condition, click Add.
To remove one or more conditions, click Delete, and then select the check box for the condition or conditions you want to delete.