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When I try to use
button.kf.setImage(with: url, for: .normal, placeholder: nil, options: nil, progressBlock: nil, completionHandler: nil) on my UIButton it only shows blue colour image instead of loading actual image
I am attaching sample code please run and check.

XCode 9.2
Swift 4.0
Kingfisher 4.6.2
[Add anything else here]
Button images are rendered as template by default. You may want to use the original version. Try something like this:
let modifier = AnyImageModifier { return $0.withRenderingMode(.alwaysOriginal) }
button.kf.setImage(with: url, for: .normal, placeholder: nil, options: [.imageModifier(modifier)], progressBlock: nil, completionHandler: nil)
I set the button's type to custom and it worked. (instead of system)
Most helpful comment
Button images are rendered as template by default. You may want to use the original version. Try something like this: