Dim pColor As IRgbColor

    Set pColor = New RgbColor

    pColor.Red = 70
    pColor.Green = 130
    pColor.Blue = 180

    Dim pLineSym As ISimpleLineSymbol
    Set pLineSym = New SimpleLineSymbol

     pLineSym.Color = pColor

     Dim pRenderer As ISimpleRenderer
     Set pRenderer = New SimpleRenderer

     Set  pRenderer.Symbol = pLineSym

     Dim pGFLayer As IGeoFeatureLayer
     Set pGFLayer = pFLayer

    Set pGFLayer.Renderer = pRenderer