Hello together,
ich need to know what Property i need to change if i want to change the complete Backcolor if the Grid.
As example i load you an Picture i can change the backcolor, but the is the white stripe this wold not change.
What property should i change the complte grid is gray?

I think that the white bar you see is the iGrid header. If you took this screenshot in Windows 10, then you see the header using the Windows 10 visual theme. To set a specific background color for this item, turn the use of visual styles off (SEE the iGrid.Header.UseXPStyles property) and set the required color with the iGrid.Header.BackColor property.