Hi,
I suppose that you're talking about the CSS from here:
www.hikashop.com/support/documentation/2...y-color.html#results
As you can see, it bases itself on the class hikashop_product_characteristics_table
So since you want to modify the show_default view file, you could simply use instead a new class that you would put in a div around the area where the characteristics are displayed on the product page.
That way, it would only affect the products using this new layout.
And regarding how to create that new layout, it's quite easy. You need to edit the show_default view file, and when you save your changes, you can enter a new name in the input at the top of the view file edition interface. That way, if will be saved as a new view file and you'll be able to select it instead of the "default" layout in the "product page layout" setting of the products.