Phalaenopsis Has Black Roots

[Marivic]

Hello,
I'm new to growing orchids and I recently got a phalaenopsis that was already in bad condition. The plant had limp leaves, and the back of the leaves have a purplish hue to them. I cut the flower stem and repotted it, about 3 weeks ago. I also started soaking the roots in water during the day since the leaves still have not improved. I noticed that the center roots feel healthy but they are black while all the other roots look normal. Does anyone know if this is some sort of ailment or if this guy still has a fighting chance?