Sub Highlight_Error_Digits()
    Dim ws As Worksheet, minLen As Long, i As Long, c As Range, clr As Long
    Dim Pi_String As String, Pi_Entrd_String As String 'every variable needs a type
    
    Set ws = ThisWorkbook.Worksheets("Pi_Key'd_In")
    Pi_String = ws.Range("C14").Value
    Pi_Entrd_String = ws.Range("C13").Value
    minLen = Application.Min(Len(Pi_String), Len(Pi_Entrd_String))
    
    Set c = ws.Range("C16")
    c.NumberFormat = "@" 'set format to "Text"
    c.Font.Color = vbBlack 'reset cell font
    c.Value = Pi_Entrd_String
    For i = 1 To minLen
        clr = IIf(Mid(Pi_String, i, 1) = Mid(Pi_Entrd_String, i, 1), vbBlack, vbRed) 'Color?
        c.Characters(i, 1).Font.Color = clr
    Next i
/* this next part is what is not working */
    If Pi_Entrd_String = Pi_String Then
        c.Font = vbWhite
        c.Value = ""
    End If
End Sub

/* received help with highlighting the errors and that works fine, but if there are no errors then I do not want to write the pi string to Range(“C16”) */