Change color of UISwitch in "off" state

Question

My solution with #swift2:

let onColor  = _your_on_state_color
let offColor = _your_off_state_color

let mSwitch = UISwitch(frame: CGRect.zero)
mSwitch.on = true

/*For on state*/
mSwitch.onTintColor = onColor

/*For off state*/
mSwitch.tintColor = offColor
mSwitch.layer.cornerRadius = mSwitch.frame.height / 2.0
mSwitch.backgroundColor = offColor
mSwitch.clipsToBounds = true

Result:

Try using this

yourSwitch.backgroundColor = [UIColor whiteColor];
youSwitch.layer.cornerRadius = 16.0;

All thanks to @Barry Wyckoff.

You can use the tintColor property on the switch.

switch.tintColor = [UIColor redColor]; // the "off" color
switch.onTintColor = [UIColor greenColor]; // the "on" color

Note this requires iOS 5+

Swift IBDesignable

import UIKit
@IBDesignable

class UISwitchCustom: UISwitch {
    @IBInspectable var OffTint: UIColor? {
        didSet {
            self.tintColor = OffTint
            self.layer.cornerRadius = 16
            self.backgroundColor = OffTint
        }
    }
}

set class in Identity inspector

change color from Attributes inspector

Output

Here's a pretty good trick: you can just reach right into the UISwitch's subview that draws its "off" background, and change its background color. This works a lot better in iOS 13 than it does in iOS 12:

if #available(iOS 13.0, *) {
    self.sw.subviews.first?.subviews.first?.backgroundColor = .green
} else if #available(iOS 12.0, *) {
    self.sw.subviews.first?.subviews.first?.subviews.first?.backgroundColor = .green
}

The Best way to manage background color & size of UISwitch

For now it's Swift 2.3 code

import Foundation
import UIKit

@IBDesignable
class UICustomSwitch : UISwitch {

    @IBInspectable var OnColor : UIColor! = UIColor.blueColor()
    @IBInspectable var OffColor : UIColor! = UIColor.grayColor()
    @IBInspectable var Scale : CGFloat! = 1.0

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.setUpCustomUserInterface()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.setUpCustomUserInterface()
    }


    func setUpCustomUserInterface() {

        //clip the background color
        self.layer.cornerRadius = 16
        self.layer.masksToBounds = true

        //Scale down to make it smaller in look
        self.transform = CGAffineTransformMakeScale(self.Scale, self.Scale);

        //add target to get user interation to update user-interface accordingly
        self.addTarget(self, action: #selector(UICustomSwitch.updateUI), forControlEvents: UIControlEvents.ValueChanged)

        //set onTintColor : is necessary to make it colored
        self.onTintColor = self.OnColor

        //setup to initial state
        self.updateUI()
    }

    //to track programatic update
    override func setOn(on: Bool, animated: Bool) {
        super.setOn(on, animated: true)
        updateUI()
    }

    //Update user-interface according to on/off state
    func updateUI() {
        if self.on == true {
            self.backgroundColor = self.OnColor
        }
        else {
            self.backgroundColor = self.OffColor
        }
    }
}