Negative Stock Levels

I allow people to order items even when they are out of stock.

The problem I am having is that people do not seem to notice the - sign in front of numbers when the QTY is below zero.

"Well it shows you have 7 on hand why haven't your shipped"

"Sorry, but we have -7 on hand"

How can I change the font color on the qty to red when the qty<0?

I know its just going to be a simple line if php code

if(product_qty<)
{
//display red
}
else
{
//code as it is now
}

But I am not sure where to place it or the exact specifics

Thanks

You would need to alter the tpl_product_info_display.php and catch the value of:
$products_quantity

The line reads something like:

  <?php echo (($flag_show_product_info_quantity == 1) ? '<li>' . $products_quantity . TEXT_PRODUCT_QUANTITY . '</li>'  : '') . "\n"; ?>