How to set a special color for actual date in Gantt?

There are two options:

1. You can add a separator:

DayPilotGantt1.Separators.Add(DateTime.Today, Color.Red);

2. You can change the background color of the cells:

protected void DayPilotGantt1_BeforeCellRender(object sender, DayPilot.Web.Ui.Events.Gantt.BeforeCellRenderEventArgs e)
{
  if (e.Start <= DateTime.Today && DateTime.Today < e.End) {
    e.BackgroundColor = Color.Red;
  }
}