Question

I already set a standard text and color for the text and when the textbox is clicked I clear the text for the User type text and define color black.
on click event:

 if (txtbox.Text == "Ex.: [text test]")
            {
                txtbox.Text = string.Empty;
                txtbox.ForeColor = Color.Black;
            }

I want to set a default text if the textbox is empty and the focus is in another textbox, so if the User clicking or pressing tab.

Answer 1

  private void textBox1_Validating(object sender, EventArgs e)
    {
        if (string.IsNullOrWhiteSpace(textBox1.Text))
        {
            //Your logic here or the color you want 
        }
    }