Sub FillRows()
    Dim intI As Integer
    
    For intI =  1  To  20 
        If (intI Mod  2 ) =  0  Then
            Worksheets("Лист1").Rows(intI).Interior.Color = RGB( 0 ,  0 ,  255 )
        End If
    Next
End Sub

=ОСТАТ(СТРОКА(A1); 2 )= 0 

Sub ConditionColor()
    On Error GoTo HandleErr

    MsgBox Range("A1").FormatConditions( 1 ).Interior.Color

ExitHere:
    Exit Sub

HandleErr:
    Select Case Err.Number
        Case  1004 
            MsgBox "Условное форматирование не применено."
        Case Else
            MsgBox Err.Number & ": " & Err.Description
    End Select
    Resume ExitHere
End Sub