How to change row color in datagridview?

Question

You need to loop through the rows in the datagridview and then compare values of columns 7 and 10 on each row.

Try this:

foreach (DataGridViewRow row in vendorsDataGridView.Rows) 
     if (Convert.ToInt32(row.Cells[7].Value) < Convert.ToInt32(row.Cells[10].Value)) 
     {
         row.DefaultCellStyle.BackColor = Color.Red; 
     }

I was just investigating this issue (so I know this question was published almost 3 years ago, but maybe it will help someone... ) but it seems that a better option is to place the code inside the RowPrePaint event so that you don't have to traverse every row, only those that get painted (so it will perform much better on large amount of data:

Attach to the event

this.dataGridView1.RowPrePaint 
    += new System.Windows.Forms.DataGridViewRowPrePaintEventHandler(
        this.dataGridView1_RowPrePaint);

The event code

private void dataGridView1_RowPrePaint(object sender, DataGridViewRowPrePaintEventArgs e)
{
    if (Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[7].Text) < Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[10].Text)) 
    {
        dataGridView1.Rows[e.RowIndex].DefaultCellStyle.BackColor = Color.Beige;
    }
}

You're looking for the CellFormatting event.
Here is an example.

I had trouble changing the text color as well - I never saw the color change.

Until I added the code to change the text color to the event DataBindingsComplete for DataGridView. After that it worked.

I hope this will help people who face the same problem.