Dynamic text Colour on DateTimePicker UserControl

I am creating a windows user control based on a DateTimePicker. The control is set to show just the time so it displays thus:

I have a public property TimeIsValid:

public bool TimeIsValid
{
   get { return _timeIsValid; }
   set
   {
      _timeIsValid = value;
      Refresh();
   }
}

and when this is set to false I want the text to turn red. So I have overridden the OnPaint with the following code:

    protected override void OnPaint(PaintEventArgs e)
     {
        base.OnPaint(e);

        e.Graphics.DrawString(Text, Font, 
        _timeIsValid ? new SolidBrush(Color.Black) : new SolidBrush(Color.Red),
        ClientRectangle);

     }

This did nothing. So in the in the constructor I have added the following code:

public DateTimePicker(IContainer container)
{
    container.Add(this);
    InitializeComponent();
    //code below added
    this.SetStyle(ControlStyles.UserPaint, true);
}

Which works, kind of, but causes some alarming results ie

The control does not appear selected even when it is.

Clicking on the up/down controls changes the underlying value of the control but does not always change the visible value.

The control does not repaint properly when changing its value via another control but moving a mouse over the control seems to force the repaint.

Look at this weirdness for instance ...

What am I missing?

---

It's a lousy control to try to inherit from, but some things to try:

Add the double-buffer:

this.SetStyle(ControlStyles.UserPaint | 
              ControlStyles.OptimizedDoubleBuffer, true);

Clear the background and draw the highlight if the control has the focus:

protected override void OnPaint(PaintEventArgs e) {
  e.Graphics.Clear(Color.White);
  Color textColor = Color.Red;
  if (this.Focused) {
    textColor = SystemColors.HighlightText;
    e.Graphics.FillRectangle(SystemBrushes.Highlight, 
                             new Rectangle(4, 4, this.ClientSize.Width - SystemInformation.VerticalScrollBarWidth - 8, this.ClientSize.Height - 8));
  }
  TextRenderer.DrawText(e.Graphics, Text, Font, ClientRectangle, textColor, Color.Empty, TextFormatFlags.VerticalCenter);
  base.OnPaint(e);
}

and invalidate the control when the value changes:

protected override void OnValueChanged(EventArgs eventargs) {
  base.OnValueChanged(eventargs);
  this.Invalidate();
}

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