One way you can do this is to handle the DrawCellBackground event and draw the background there yourself. In order for this event to be hit on a particular cell, you must set that cell''s style.Interior = Syncfusion.Drawing.BrushInfo.Empty;. So, for example, you could have code like this:
//in form.load set the styles empty on these cells.
this.gridControl1[2,2].Interior = Syncfusion.Drawing.BrushInfo.Empty;
this.gridControl1[2,3].Interior = Syncfusion.Drawing.BrushInfo.Empty;
this.gridControl1[2,4].Interior = Syncfusion.Drawing.BrushInfo.Empty;
this.gridControl1[3,2].Interior = Syncfusion.Drawing.BrushInfo.Empty;
this.gridControl1[3,3].Interior = Syncfusion.Drawing.BrushInfo.Empty;
this.gridControl1[3,4].Interior = Syncfusion.Drawing.BrushInfo.Empty;
this.gridControl1[4,2].Interior = Syncfusion.Drawing.BrushInfo.Empty;
this.gridControl1[4,3].Interior = Syncfusion.Drawing.BrushInfo.Empty;
this.gridControl1[4,4].Interior = Syncfusion.Drawing.BrushInfo.Empty;
//the handler
private void gridControl1_DrawCellBackground(object sender, GridDrawCellBackgroundEventArgs e)
{
Rectangle rect = e.TargetBounds;
int off = 3;
rect = new Rectangle(rect.X + off, rect.Y + off, rect.Width - 2 * off, rect.Height - 2 * off);
Color c = (e.Style.Interior.IsEmpty) ? Color.Red : e.Style.BackColor;
using (Brush b = new SolidBrush(c))
{
e.Graphics.FillRectangle(b, rect);
}
e.Cancel = true;
}