VBAで折れ線グラフの線やマーカーを変更する

Sub chart()

    ActiveSheet.ChartObjects("graph").Activate
    ActiveChart.FullSeriesCollection(3).Select
    
'マーカーの型とサイズを指定
    With Selection
        .MarkerStyle = 8
        .MarkerSize = 5
    End With

'マーカーの色を指定
    With Selection
        .MarkerBackgroundColor = RGB(255, 0, 0)
        .MarkerForegroundColor = RGB(255, 0, 0)
    End With

'ラインの色と太さと型を指定
    With Selection.Format.Line
        .Visible = msoTrue
        .ForeColor.RGB = RGB(255, 0, 0)
        .Weight = 2.25
        .DashStyle = msoLineSolid
    End With
    
    ActiveChart.FullSeriesCollection(1).Select
'マーカーを消す
    Selection.MarkerStyle = xlNone
'ラインの色と太さと型を指定
    With Selection.Format.Line
        .Visible = msoTrue
        .ForeColor.RGB = RGB(0, 0, 255)
        .Weight = 1.5
        .DashStyle = msoLineSysDash
    End With

    ActiveChart.FullSeriesCollection(2).Select
'マーカーを消す
    Selection.MarkerStyle = xlNone
'ラインの色と太さと型を指定
    With Selection.Format.Line
        .Visible = msoTrue
        .ForeColor.RGB = RGB(0, 0, 255)
        .Weight = 1.5
        .DashStyle = msoLineSysDash
    End With

End Sub