Question: Before asking the question, I have searched stackoverflow, find a related post:

[change segmentControl border color](https://stackoverflow.com/questions/19041035/iphone-ios7-segmented-uisegmentedcontrol-change-only-border-color) 

But we can see it is in `objective-c` language.

So how can we change the borderColor of `UISegmentControl` in `swift` ?

Answer: 
You literally just have to convert the code to swift...

```
let customSegmentedControl = UISegmentedControl.appearance()    
customSegmentedControl.setTitleTextAttributes([NSForegroundColorAttributeName : UIColor.red], for: UIControlState.normal)

```

But I believe the code you posted changes the actual color of the letters, not the color outside. The color outside is called "tint" and it's changed like this:

```
customSegmentedControl.tintColor = UIColor.blue

```

**EDIT: For ONLY changing the border**

Since each segment in the SegmentedControl is an actual UIView you can access them directly and customize them per your needs as in [this answer](https://stackoverflow.com/questions/34758590/change-border-color-of-uisegmentedcontrol).

Or you can set the "background image" which I believe can be set to the color you need. (Although the method above seems less complicated)
Add the outlet

```
@IBOutlet weak var customSegment: UISegmentedControl!

```

then in your viewDidload method

```
    customSegment.layer.borderWidth = 1.0
    customSegment.layer.cornerRadius = 5.0
    customSegment.layer.borderColor = UIColor.red.cgColor
    customSegment.layer.masksToBounds = true

```

[![enter image description here](https://i.stack.imgur.com/B7UWt.png)](https://i.stack.imgur.com/B7UWt.png)