I'm developing an assistive technology application (in C#) that overlays information on top of the currently open window. It detects clickable elements, and labels them.

To do this, I'm currently creating a borderless, transparent window with TopMost set to "true", and drawing the labels on that. This means there is always a window hovering in front of the current application, on which I can draw the labels.

The problem is, this window doesn't cover the right-click menu - only other windows. When the user right-clicks, the context menu is drawn above the overlay. 

I need to be able to label elements in the right-click menu, but I can't draw on top of it with the current implementation. Does anybody know of a solution? 

Edit: This is the relevant code for drawing the overlay. I've set the form options in the form designer, not in the code explicity, so I'm not sure how much it will help. I've removed the code not related to drawing, or the form itself:

```
public partial class OverlayForm : Form
{
    public OverlayForm()
    {

    }

    protected override void OnPaint(PaintEventArgs eventArgs)
    {
        base.OnPaint(eventArgs);
        Graphics graphics = eventArgs.Graphics;
        Brush brush = new SolidBrush(this.labelColor);
        foreach (ClickableElement element in this.elements)
        {
            Region currentRegion = element.region;
            graphics.FillRegion(brush, currentRegion);
        }
    }    
}

```