Bovine Viral Diarrhoea

Experimenting with a simple vertical navigation for a quite complex site structure (nested sections up to three levels deep) - eg in this case located in Disease Information > Bovine Viral Diarrhoea.

Using tone depth to signify site depth (darker is deeper) but not sure if the two arrows quite work to orientate properly - i.e. horizontal = you are here whilst vertical = you are in this section.

Interested in any feedback.

Wonder if indentation of child pages as well as tonal change would be an improvement - always a fan of never using two design elements where one would suffice!