Border has background color seeping through it

I'm setting the background color to a white border and the border is seeping through the background.I'm looking to have the blue line gone. Can you please suggest a solution to this problem?

Here is my code below. And there is an image of what I'm talking about below.

[

self.imageView.layer.borderColor = UIColor.white.cgColor
self.imageView.layer.borderWidth = 3
self.imageView.backgroundColor = UIColor.blue
self.imageView.layer.cornerRadius = CGFloat(CircleDiameter/2)