Well, while there'r far more knowledgable people than me, from what I've read, root rot will smell rotten, and feel slimey and you can easily tug out rotted roots. But you say yours feel normal and dont smell like rot, so I'd have to guess you're ok.

While you pull them up like that, you could always squirt some H2O2 directly on the darker rootmass and call it a day I think.