method FormatConditionalAppearances.Add (Key as String, [Name as Variant], [Expression as Variant])
Adds a FormatConditionalAppearance object and returns a reference to the newly created object.

TypeDescription
Key as String A String expression that specifies the unique key of the FormatConditionalAppearance object. The Key of the FormatConditionalAppearance should include only alpha-numeric characters, any other character will be ignored.
Name as Variant A String expression that indicates the HTML caption to be displayed on the control's context menu.
Expression as Variant A String expression that defines the conditional-expression to apply the current FormatConditionalAppearance. The Expression property defines the conditional-expression to apply the current format. For instance, "len(value) != 0" indicates any not-empty value.
ReturnDescription
FormatConditionalAppearanceA FormatConditionalAppearance object being created.

By default, the FormatConditionalAppearances collection contains the following keys: "positive", and "negative". The FormatConditionalAppearances helps you to provide conditional-format for your data, or in other words, ability to highlight values that matches a specified expression. Use the Clear method to remove all FormatConditionalAppearance objects from the FormatConditionalAppearances collection. Use the Remove method to remove a FormatConditionalAppearance object giving its key. Use the Item property to access a FormatConditionalAppearance object giving its key. The Key property indicates the key of the FormatConditionalAppearance object. The FormatAppearances collection provides formatting for entire column, no matter of what values it contains. 

The following screen shows shows the negative/positive values with different colors/EBNs:

By default, the FormatConditionalAppearances collection contains the following:

If the PivotBarVisible property includes the exPivotBarAllowFormatConditionalAppearance, the control's context menu include the "Conditional" item as shown bellow:

The FormatConditionalAppearance object changes the visual appearance of your values as listed: