Field background color change with value

Fantastic plugin, loving it!

Is it possible to change the background color of a field based on the value shown in it? I have found and modified an answer you gave to change the text color.

PREC((function(){
var result = ((fieldname117/fieldname116)*100),
color = IF(result<=fieldname326, 'red', 'green');

jQuery('.margin-profit-field input ').css('color', color);
return result;
})(),0)

This I got working but I want to change the background color of the field rather than the numbers within it.

Thanks!