Hi Glen,
You can simply use:
this.gridControl1.GridLineColor = System.Drawing.Color.Transparent;
and this should make the grid lines transparent, with the (pretty old) version 2.5 or with the (current) version 3.8.
Best regards,
Ghislain
Technical Support and software developer
Xceed Software Inc.
Knowledge Base : http://xceed.com/kb/
Update Center : http://xceed.com/updates/
Documentation Center : http://xceed.com/doc/
For everything else, there is Google