Как в PictureBox используя TrackBar изменять цвет? - Visual Basic .NET

PictureBox1.Image = colorProcessing(bb, 15.5, 2, 3)
'…
Private Function colorProcessing(ByVal img As Bitmap, ByVal rr As Single, ByVal gg As Single, ByVal bb As Single, _
                                 Optional ByVal drr As Single = 0, Optional ByVal dgg As Single = 0, Optional ByVal dbb As Single = 0, _
                                 Optional ByVal Gamma As Single = 1, Optional ByVal aa As Single = 1.0) As Bitmap
    Dim copy As Bitmap = New Bitmap(img.Width, img.Height)
    Dim ia As ImageAttributes = New ImageAttributes
    Dim myColorMatrix As New ColorMatrix
    With myColorMatrix
        'увеличить в k раз
        .Matrix00 = rr ' Red
        .Matrix11 = gg ' Green
        .Matrix22 = bb ' Blue
        .Matrix33 = aa ' alpha
        .Matrix44 = 1.0 'w
        'добавить к имеющимся
        .Matrix40 = drr
        .Matrix41 = dgg
        .Matrix42 = dbb
    End With
    ia.SetColorMatrix(myColorMatrix)
    ia.SetGamma(Gamma) '0.1 - 5.0
    Dim g As Graphics = Graphics.FromImage(copy)
    g.DrawImage(img, New Rectangle(0, 0, img.Width, img.Height), 0, 0, img.Width, img.Height, GraphicsUnit.Pixel, ia)
    g.Dispose()
    img.Dispose()
    Return copy
End Function