how to change the particular cell color in gridview based on if condition

1.In the case of ASP.NET projects, in the grid view's RowDataBound event you could do it like in the next example:

protected void _yourGridView_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                if (e.Row.Cells[0].Text == "someValue") //Here is the condition!
                {
                    //   
                    //Change the cell color.
                    e.Row.Cells[0].ForeColor = System.Drawing.Color.Red;
                    //
                    //Change the back color.
                    e.Row.Cells[0].BackColor = Color.Yellow;
                    
                }
            }
        }

2.In the case of Windows Forms you should use DataGridView objects, and to change the colors you have to do it by using DataBindingComplete event like in the next example:

private void _yourDataGridView_DataBindingComplete(object sender,
    DataGridViewBindingCompleteEventArgs e)
{
 //...
 //
if(condition) //Your condition!
{
_yourDataGridView.Item(0, 1).Style.ForeColor = Color.Red;
_yourDataGridView.Item(0, 1).Style.BackColor = Color.Yellow;
}
}

I normally use the CellFormatting event. It's fired everytime a row is showed in the Datagrid. You've got an example here[^]

https://www.aspsnippets.com/demos/1082/