ListBox and ComboBox in UserForm not responding to code

When I open the Userform & tab through controls, this code is not having any effect?

Private Sub cmbMonth_BeforeUpdate(ByVal Cancel As MSForms.ReturnBoolean)

    If IsEmpty(cmbMonth.Value) Then
        cmbMonth.BackColor = rgbPink
        Cancel = True
    End If
End Sub
Private Sub LstCustomer_AfterUpdate()

    If IsEmpty(LstCustomer.Value) Then
        lblCustomer.ForeColor = vbRed
        Cancel = True
    End If
End Sub

Thanks in advance

If you are just tabbing through the controls, then you have not updated the control & therefore the code will not run.
Depending on what you are trying to do , you could use the Exit event instead

If the user does not select anything from the list, I want to change the color of the label to red to remind the user to make a selection.

In that case use the exit event.

Thanks for your reply but this is not working? I launch the form in Excel & if I don't make a selection from the Listbox, I want to change the color of the label to remind the user to make a selection. I removed the line of code "Cancel = True" for the Listbox:

Private Sub LstCustomer_AfterUpdate()

    If IsEmpty(LstCustomer.Value) Then
        lblCustomer.ForeColor = vbRed
        
    End If
End Sub

I also tried the Exit event but it also did not work?

I am confused why are you attempting to use either of those events as they are inappropriate.
Without your workbook it is difficult to see in what context you are using the events.
See the yellow banner at the head of the page to help us to help you.
To check for empty interrogate the listcount.

If LstCustomer.ListCount = 0 Then MsgBox "Listbox empty"

Can you please supply a sample workbook?

Thanks - I have attached an example file. If you click "Post Record" with no selections, the month code works but not the ListBox code.
Thanks in advance

Thanks for that.
You need to remove the Exit Sub lines, otherwise it never checks the listbox, you also need to change the listbox part like

Private Sub cmdPostData_Click()

    If cmbMonth.Value = "" Then
        cmbMonth.BackColor = vbRed
    End If
    
    If ListBox1.ListIndex = -1 Then
        lblProduct.ForeColor = vbRed
    End If
    
    Range("Product").Value = ListBox1.Value
    Range("Month").Value = cmbMonth.Value
    
End Sub

Thank you - (ListIndex = -1) was the solution. Spent so much time trying to figure this out but learnt a lot of other stuff! Thanks, once again

You're welcome & thanks for the feedback