How can I change image tintColor in iOS and WatchKit

Here's a category that should do the trick

@interface UIImage(Overlay)
@end

@implementation UIImage(Overlay)

- (UIImage *)imageWithColor:(UIColor *)color1
{
        UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
        CGContextRef context = UIGraphicsGetCurrentContext();
        CGContextTranslateCTM(context, 0, self.size.height);
        CGContextScaleCTM(context, 1.0, -1.0);
        CGContextSetBlendMode(context, kCGBlendModeNormal);
        CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
        CGContextClipToMask(context, rect, self.CGImage);
        [color1 setFill];
        CGContextFillRect(context, rect);
        UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return newImage;
}
@end

so you would do:

theImageView.image = [theImageView.image imageWithColor:[UIColor redColor]];

iOS
For an iOS app, in Swift 3, 4 or 5:

theImageView.image = theImageView.image?.withRenderingMode(.alwaysTemplate)
theImageView.tintColor = UIColor.red

For Swift 2:

theImageView.image = theImageView.image?.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate)
theImageView.tintColor = UIColor.redColor()

Meanwhile, the modern Objective-C solution is:

theImageView.image = [theImageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
[theImageView setTintColor:[UIColor redColor]];

---

Watchkit
In WatchKit for Apple Watch apps, you can set the tint color for a template image.

1. You must add your image to an Asset Catalog in your WatchKit App, and set the image set to be rendered as a Template Image in the Attributes Inspector. Unlike for an iPhone app, you cannot set the template rendering in code in the WatchKit Extension at present.
2. Set that image to be used in your WKInterfaceImage in interface builder for your app
3. Create an IBOutlet in your WKInterfaceController for the WKInterfaceImage called 'theImage'...

To then set the tint color in Swift 3 or 4:

theImage.setTintColor(UIColor.red)

Swift 2:

theImage.setTintColor(UIColor.redColor())

To then set the tint color in Objective-C:

[self.theImage setTintColor:[UIColor redColor]];

If you use a template image and do not apply a tint colour, the Global Tint for your WatchKit app will be applied. If you have not set a Global Tint, theImage will be tinted light blue by default when used as a template image.

In storyboard and image Assets. you can change this two also:

Update the Render Mode to Template Image

Update the tint Color in Views.

I had to do this in Swift using an extension.

I thought I'd share how I did it:

extension UIImage {
    func imageWithColor(color1: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        color1.setFill()

        let context = UIGraphicsGetCurrentContext() as CGContextRef
        CGContextTranslateCTM(context, 0, self.size.height)
        CGContextScaleCTM(context, 1.0, -1.0);
        CGContextSetBlendMode(context, CGBlendMode.Normal)

        let rect = CGRectMake(0, 0, self.size.width, self.size.height) as CGRect
        CGContextClipToMask(context, rect, self.CGImage)
        CGContextFillRect(context, rect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext() as UIImage
        UIGraphicsEndImageContext()

        return newImage
    }
}

Usage:

theImageView.image = theImageView.image.imageWithColor(UIColor.redColor())

Swift 4

extension UIImage {
    func imageWithColor(color1: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        color1.setFill()

        let context = UIGraphicsGetCurrentContext()
        context?.translateBy(x: 0, y: self.size.height)
        context?.scaleBy(x: 1.0, y: -1.0)
        context?.setBlendMode(CGBlendMode.normal)

        let rect = CGRect(origin: .zero, size: CGSize(width: self.size.width, height: self.size.height))
        context?.clip(to: rect, mask: self.cgImage!)
        context?.fill(rect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return newImage!
    }
}

Usage:

theImageView.image = theImageView.image?.imageWithColor(color1: UIColor.red)