  The Isolated Horizons (IH) formalism, together with a simple phenomenological
model for colored black holes has been used to predict non-trivial formulae
that relate the ADM mass of the solitons and hairy Black Holes of
Gravity-Matter system on the one hand, and several horizon properties of the
black holes in the other. In this article, the IH formalism is tested
numerically for spherically symmetric solutions to an Einstein-Higgs system
where hairy black holes were recently found to exist. It is shown that the mass
formulae still hold and that, by appropriately extending the current model, one
can account for the behavior of the horizon properties of these new solutions.
An empirical formula that approximates the ADM mass of hairy solutions is put
forward, and some of its properties are analyzed.
