Loreal in general is good stuff, Loreal Paris is probably my favorite auburn brown because of the very natural color and it seemed like it was the gentlest on my hair. All the products I've tried have smelled like chemicals to some degree, but the different products smell like different chemicals. Is it something like the ammonia or something your bf doesn't like? If I had the same problem and loved my dye, I would just look for a stronger smelling shampoo. The kinds with some herb scents mixed in could mask whatever bothers him.
Hope this helps!