Set alpha of background of UIButton but not the title

This works for me:

self.myButton.backgroundColor = [UIColor clearColor];

or if you don't want to have it completely clear, but still with transparency you can use:

self.myButton.backgroundColor = [UIColor colorWithRed:200.0/255.0 green:200.0/255.0 blue:200.0/255.0 alpha:0.5];

The second example would give you gray color with alpha 0.5.

SWIFT 4 Update

myButton.backgroundColor = .clear

OR

myButton.backgroundColor = UIColor(red: 200.0/255.0, green: 200.0/255.0, blue: 200.0/255.0, alpha:0.5)

You can also change the alpha of the color in the storyboard,

see attached image:

In Swift:

import UIKitclass SignInUpMenuTableViewControllerBigButton: UIButton {    required init(coder aDecoder: NSCoder) {        super.init(coder: aDecoder)        self.applyCustomDesign()    }    func applyCustomDesign() {        // We set the background color of the UIButton.        self.clearHighlighted()    }    override var highlighted: Bool {        didSet {            if highlighted {                self.highlightBtn()            } else {                self.clearHighlighted()            }        }    }    func highlightBtn() {        self.backgroundColor = UIColor.whiteColor().colorWithAlphaComponent(0.0)    }    func clearHighlighted() {        self.backgroundColor = UIColor.whiteColor().colorWithAlphaComponent(0.05)    }}

Swift 4.2

import UIKitclass SignInUpMenuTableViewControllerBigButton: UIButton {    required init(coder aDecoder: NSCoder) {        super.init(coder: aDecoder)        self.applyCustomDesign()    }    func applyCustomDesign() {        // We set the background color of the UIButton.        self.clearHighlighted()    }    override var highlighted: Bool {        didSet {            if highlighted {                self.highlightBtn()            } else {                self.clearHighlighted()            }        }    }    func highlightBtn() {        self.backgroundColor = UIColor.whiteColor().withAlphaComponent(0.0)    }    func clearHighlighted() {        self.backgroundColor = UIColor.whiteColor().withAlphaComponent(0.05)    }}