I came across a post and found the background for a chart witha paneled indicator, Like if you have a MACD or multipanel indicator, you cant change the background with BackBrushesAll.
Since Ninjas background brushs is blacker than outer space and then next darkest is lighter than SNOW, we could all benefit from changing are backgrounds to a calming Dark gray black with:
Pop in OnRender:
chartControl.Properties.ChartBackground = new System.Windows.Media.SolidColorBrush (System.Windows.Media.Color.FromArgb (255,22, 26, 37));
Modify first parameter BYTE to transparency
Bye.