Theming Product Display page dependent on product type
I have defined different product types and a common content-type named "Product Display" referencing products. I need to theme products of different product types differently, i.e. different background colors for the product title.
The question is, on the Product Display page, how to fetch information about the product type. I already tried to apply field templates via Display Suite, which had no effect at all. I don't want to use Views. I don't want to create different content-types for Product Display.
Is there any way to get the field product->type into the node page?