Color gridview cell thru javascript

Hi,
.Net 2.0, C#
I have a template column with a textbox in a gridview. When the user enters a value in the textbox for a row,I validate the value and based on some calculations I have to color the back ground of the cell in which the textbox is placed. I pass the text box control to my javascript function to validate. when i use
 "txtControl.parentElement.parentElement.style.backgroundColor='#FF0000';" - this sets the color for the entire row. Is there any way to color only that particular cell in that row? (The template column is the 3rd column in the grid). Any help is greatly appreciated.