Change UIButton BorderColor in Storyboard

Swift 4, Xcode 9.2 - Use IBDesignable and IBInspectable to build custom controls and live preview the design in Interface Builder.

Here is a sample code in Swift, place just below the UIKit in ViewController.swift:

@IBDesignable extension UIButton {

    @IBInspectable var borderWidth: CGFloat {
        set {
            layer.borderWidth = newValue
        }
        get {
            return layer.borderWidth
        }
    }

    @IBInspectable var cornerRadius: CGFloat {
        set {
            layer.cornerRadius = newValue
        }
        get {
            return layer.cornerRadius
        }
    }

    @IBInspectable var borderColor: UIColor? {
        set {
            guard let uiColor = newValue else { return }
            layer.borderColor = uiColor.cgColor
        }
        get {
            guard let color = layer.borderColor else { return nil }
            return UIColor(cgColor: color)
        }
    }
}

If you go to the Attributes inspectable of the view, you should find these properties visually, edit the properties:

The changes are also reflected in User Defined Runtime Attributes:

Run in build time and Voila! you will see your clear rounded button with border.

For Swift:

Swift 3:

extension UIView {

    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }

    @IBInspectable var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }

    @IBInspectable var borderColor: UIColor? {
        get {
            return UIColor(cgColor: layer.borderColor!)
        }
        set {
            layer.borderColor = newValue?.cgColor
        }
    }
}

Swift 2.2:

extension UIView {

    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }

    @IBInspectable var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }

    @IBInspectable var borderColor: UIColor? {
        get {
            return UIColor(CGColor: layer.borderColor!)
        }
        set {
            layer.borderColor = newValue?.CGColor
        }
    }
}

I got answer. Change borderColor instead of layer.borderColor:

and add this code in .m file:

#import <QuartzCore/QuartzCore.h>
@implementation CALayer (Additions)

- (void)setBorderColorFromUIColor:(UIColor *)color
{
    self.borderColor = color.CGColor;
}

@end

Tick properties in Attribute Inspector