Header colors of the highlighted row and column

I have solved with the settings of visual studio. 

I tried both of them but nothing has chnaged.

You can achieve this by handling the CellFormatting event of the DataGridView. In this event, you can check if the cell in the first column is selected and then change its style. Here’s an example:

private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
    if (e.ColumnIndex == 0) // Assuming the S.No column is the first column
    {
        e.CellStyle.SelectionBackColor = dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.BackColor;
        e.CellStyle.SelectionForeColor = dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.ForeColor;
    }
}

In this code, dataGridView1 is the DataGridView control. The CellFormatting event is fired every time a cell is painted. In the event handler, we check if the cell is in the first column (the S.No column). If it is, we set the SelectionBackColor and SelectionForeColor of the cell style to the normal back color and fore color of the cell. This will make the cell appear the same whether it is selected or not.

You can wire up the event in the form’s constructor or the Load event like this:

public Form1()
{
    InitializeComponent();
    dataGridView1.CellFormatting += dataGridView1_CellFormatting;
}

Please replace dataGridView1 with the actual name of your DataGridView control. Also, adjust the column index if your S.No column is not the first column. The column indices are 0-based, so the first column is 0, the second column is 1, and so on.

Thanks

To customize the highlighted row and column colors in a DataGridView in a .NET application, you can handle the CellPainting event and set the desired colors based on the cell being painted. Here's a sample code snippet to achieve this:

private void dataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
{
    if (e.RowIndex == -1 || e.ColumnIndex == -1)
        return;

    if (e.ColumnIndex == dataGridView1.CurrentCell.ColumnIndex)
    {
        // Set the background color for the selected column
        e.CellStyle.BackColor = Color.LightBlue;
    }

    if (e.RowIndex == dataGridView1.CurrentCell.RowIndex)
    {
        // Set the background color for the selected row
        e.CellStyle.BackColor = Color.LightBlue;
    }

    // You can customize other properties like ForeColor, SelectionBackColor, etc. as needed
}

By handling the CellPainting event and checking the current cell's row and column indices, you can dynamically set the background color to achieve the desired effect.