Hi Andrew,
Thank you for using Syncfusion products.
You can customize the row heading using GridHeaderCellRenderer class. But for simple customization like changing the color you can use BaseStylesMap. Please refer the below code snippet to achieve this:
this.gridControl1.Model.BaseStylesMap["Row Header"].StyleInfo.Interior = new BrushInfo(GradientStyle.Vertical, Color.Red, Color.FromArgb(197, 222, 255));
Kindly refer to the link below that illustrates the same:
http://websamples.syncfusion.com/samples/Grid.Windows/F70472/main.htmPlease let me know if you have any other questions.
Regards,
Subhasheela R.