Ответ 1
Войдите в событие RowCellStyle и установите ForeColor там
private void gridView1_RowCellStyle(object sender, DevExpress.XtraGrid.Views.Grid.RowCellStyleEventArgs e)
{
if(e.Column.FieldName == "Field2")
{
var data = gridView1.GetRow(e.RowHandle) as Sample;
if(data == null)
return;
if (data.Field2 < 0)
e.Appearance.ForeColor = Color.Red;
}
}