sets up a two-color gradient using two theme colors:
Sub TwoColorGradient()
Dim myChart As Chart
Dim ser As Series
Set myChart = ActiveChart
Set ser = myChart.SeriesCollection(1)
MyPic = "C:\Title1.jpg"
ser.Format.Fill.TwoColorGradient msoGradientFromCorner, 3
ser.Format.Fill.ForeColor.ObjectThemeColor = msoThemeColorAccent6
ser.Format.Fill.BackColor.ObjectThemeColor = msoThemeColorAccent2