Underline inferred axioms in queries with yellow background

As it is described in the tutorial chapter "Getting Started" http://protegeproject.github.io/protege/getting-started/ inferred axioms are highlighted with a yellow background

To reason over your ontology, open the Reasoner menu and select HermiT. Next press Ctrl+R (or CMD+R on a Mac). This will start the reasoner. After the reasoner finishes you can inspect your ontology to view inferred information. For example, select American in the class hierarchy (under NamedPizza, which is under Pizza, which is under Food, which is under DomainConcept). Notice that some of the information on the right hand side is displayed with a yellow background - this is inferred information. In other words, it is information that has been computed by the reasoner.

A debugger supporting this feature goes in line with the default behaviour of Protégé