Paint UIImage with any UIColor

UIImage+TintColor.swift

import UIKit

extension UIImage {

    func paintedImage(color: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(size, false, 0.0)

        let bounds = CGRectMake(0, 0, size.width, size.height)
        let context = UIGraphicsGetCurrentContext()

        drawInRect(bounds)
        CGContextSetFillColorWithColor(context, color.CGColor)
        CGContextSetBlendMode(context, .SourceAtop) // SourceAtop にすることで画像の透過を考慮してくれる
        CGContextFillRect(context, bounds)

        let image = UIGraphicsGetImageFromCurrentImageContext()

        UIGraphicsEndImageContext()

        return image
    }

}

/*
let image: UIImage = …
let color: UIColor = …
let paintedImage = image.paintedImage(color)
*/

// https://qiita.com/usagimaru/items/5400fa74ab538ce3804c