Orchid Roots Browning

[thebluecatapilla]

Hello All! This is my first post on the forum, and I am very excited to be here. I relatively new to orchids and have only been growing them for a little under a year so bear with me please

I recently noticed one of Phal's roots to be browning. I don't think its rot but i just wanted to verify from an expert who could identify the cause of this. The orchid community on Reddit told me it is just the absorption of Tannins, but i wanted to check here to make sure.

Pictures:
Orchid roots - Album on Imgur