I liked user4101525's answer best in theory but it doesn't actually work. Selection is not an overlay so you see whatever is under the control
Ramgy Borja's answer doesn't deal with the fact that default style is not actually a color at all so applying it doesn't help. This handles the default style and works if applying your own colors (which may be what edhubbell refers to as nasty results)
dgv.RowsDefaultCellStyle.SelectionBackColor = dgv.RowsDefaultCellStyle.BackColor.IsEmpty ? System.Drawing.Color.White : dgv.RowsDefaultCellStyle.BackColor;
dgv.RowsDefaultCellStyle.SelectionForeColor = dgv.RowsDefaultCellStyle.ForeColor.IsEmpty ? System.Drawing.Color.Black : dgv.RowsDefaultCellStyle.ForeColor;