Two stemmed phalaenopsis with sudden yellow/brow stems
 

Hi

Your Phal looks perfectly OK. Keep on watering when the roots have dryed (specific color).
The flower spikes are just following ther natural cycle, that is they are bound to dry after several months.
You Phal will grow another spike when it will feel ready.

Thank you so much Val, I was hoping that was the case! So you don't recommend trimming the stems at all?

Trimming the stems is an aesthetic matter. In nature nobody trims the stems, and the plant is able to manage everything.
Trimming the stem presents the risk of opening a door to infections (fungal, bacterial). Whenever I decide to trim a stem, I dust the cut with ground cinnamon, wich is a great natural antifungal. The cinnamon must not get on healthy roots, because it's also a desiccant and could damage the roots.

One more thing: it's good to cut the wilting/wilted flowers, because they emit acetylene, which makes the flowers around to wilt much sooner. Acetylene also comes from ripe fruit etc., therefore never put ripe fruit close to orchids.

Val's advice is good, but one correction... ethylene, not acetylene.

Oops, sorry! (I know orchids are not welders! ROTL)