Been looking around and trying to change just the border color (with a different text color) with no luck. Can change the tint, but changes both the text and border.
You can change first the tintColor and after the titleText.
//Changes Tint Color
segmentedControlName.tintColor = [UIColor colorWithRed:0/255 green:0/255 blue:0/255 alpha:1];
//TitleText to BlackColor
[[UISegmentedControl appearance] setTitleTextAttributes:@{ NSForegroundColorAttributeName : [UIColor blackColor] } forState:UIControlStateNormal];