Documentation comment for a Swift class extension

I am extending UIColor, and trying to give a description to the extended class.

My code is

/**
 - To store all colors
 - Naming Convention identifier: In lowerCamelCase with single name description
 - Naming Convention value: single name

 - example:  self.view.backgroundColor = UIColor.View.NonCompliant

 */
extension UIColor{

        /**
         - To specify all seperators' color
         */
        struct Seperators{
            static let commonSeperator = UIColor(red: 53.0/255.0, green: 126.0/255.0, blue: 167.0/255.0, alpha: 1.0)
        }
}

But Xcode still shows the original description instead of the modified description.

Does anyone know how to do this?