Hi,

You can apply a custom css class through the AddNewRowCssClass property exposed by the RowAdding behavior, or you can use a css selector, as explained in the WebDataGrid CSS Styling Guide.

An example of how to color the first cell in the AddNEwRow using the AddNewRowCssClass:

<ig:RowAdding AddNewRowCssClass="NewClass">
</ig:RowAdding>

..

tbody > tr.NewClass > td:first-child
{
    background-color: Red;
}

Please let me know if you have further questions.