I want to try a new layout for my products page. It would involve a new layout and new color scheme on every products page. There are hundreds of product pages.
My question is, how do you a/b test when the change is for more than one page?

I am calling a class products.php, and I have created a new design at products1.php. I dont know how I can send half my traffic to each class, and a/b track. How is this achieved? The same issue would arise if I wanted to test a different header throughout the site.