I took the products with me to the salon yesterday when I got my haircut/highlight. My stylist LOVED the smell, so I left what I brought with him (he's a good friend.) I can't understand what's not to like. I really love the scent, too. That's why they make chocolate and vanilla.
My thought is to take an EO and mix it in. I'd try a little bit to start (maybe to a small amount) and see if that works. I think most scents would go with the "vanilla" scent of the products. You could do lavender or lemongrass.