How can I color a UIImage in Swift?

Swift 4 and 5

extension UIImageView {
  func setImageColor(color: UIColor) {
    let templateImage = self.image?.withRenderingMode(.alwaysTemplate)
    self.image = templateImage
    self.tintColor = color
  }
}

Call like this:

let imageView = UIImageView(image: UIImage(named: "your_image_name"))
imageView.setImageColor(color: UIColor.purple)

Alternativ
For Swift 3, 4 or 5

extension UIImage {

    func maskWithColor(color: UIColor) -> UIImage? {
        let maskImage = cgImage!

        let width = size.width
        let height = size.height
        let bounds = CGRect(x: 0, y: 0, width: width, height: height)

        let colorSpace = CGColorSpaceCreateDeviceRGB()
        let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedLast.rawValue)
        let context = CGContext(data: nil, width: Int(width), height: Int(height), bitsPerComponent: 8, bytesPerRow: 0, space: colorSpace, bitmapInfo: bitmapInfo.rawValue)!

        context.clip(to: bounds, mask: maskImage)
        context.setFillColor(color.cgColor)
        context.fill(bounds)

        if let cgImage = context.makeImage() {
            let coloredImage = UIImage(cgImage: cgImage)
            return coloredImage
        } else {
            return nil
        }
    }

}

For Swift 2.3

extension UIImage {
func maskWithColor(color: UIColor) -> UIImage? {

    let maskImage = self.CGImage
    let width = self.size.width
    let height = self.size.height
    let bounds = CGRectMake(0, 0, width, height)

    let colorSpace = CGColorSpaceCreateDeviceRGB()
    let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.PremultipliedLast.rawValue)
    let bitmapContext = CGBitmapContextCreate(nil, Int(width), Int(height), 8, 0, colorSpace, bitmapInfo.rawValue) //needs rawValue of bitmapInfo

    CGContextClipToMask(bitmapContext, bounds, maskImage)
    CGContextSetFillColorWithColor(bitmapContext, color.CGColor)
    CGContextFillRect(bitmapContext, bounds)

    //is it nil?
    if let cImage = CGBitmapContextCreateImage(bitmapContext) {
        let coloredImage = UIImage(CGImage: cImage)

        return coloredImage

    } else {
        return nil
    } 
 }
}

Call like this:

let image = UIImage(named: "your_image_name")
testImage.image =  image?.maskWithColor(color: UIColor.blue)