title: Change cell Back Color in Edit mode
body: <p>I want to change the back color of a cell in a <code>DataGridView</code> when it is being edited. All solutions I tried applies the color when I get out from the cell. Because I want users to type something and in the <code>Cell_Validating</code> event if the value does not pass rules then I color the  cell disallow user from getting out the cell. Following is the code I tried:
  <br/></p>
  
  <pre><code>DataGridViewCellStyle CellStyle = new DataGridViewCellStyle();
  CellStyle.BackColor = Color.Red;
  dgvAddAssets.CurrentCell.Style = CellStyle;
  </code></pre>