Need Opinion on whether to repot Oncidium Twinkle

[Pinkeed]

I have not had Oncidiums before. I only acquired this plant on 3/4/16. I have watered and fertilized with 8-4-8 exactly once since then (this was all within the same watering). So I don't think I have had the chance to do anything to it yet except maybe put it in too much light (not sure). It's getting light from my balcony and I close the blinds partway when the light starts shining directly so the plant is not exposed to it. Temps vary from 68-72. The only other thing I can think of is that I used tap water, but I don't think it would have that effect after one go.

It is flowering, so I didn't really want to repot it until after it was done. But the yellow and brown part where the plant meets the media worries me. It looks like it might have root problems. I have seen something similar on a Dracula before and the roots were all rotted.

Should I wait or repot? It's possible this damage was already there and I just didn't notice it.