I need help

INSTRUCTIONS TO THIS CHALLENGE: In the editor, I’ve declared a struct named RGBColor that models a color object in the RGB space.

Your task is to write a custom initializer method for the object. Using the initializer assign values to the first four properties. Using the values assigned to those properties create a value for the description property that is a string representation of the color object.

For example, given the values 86.0 for red, 191.0 for green, 131.0 for blue and 1.0 for alpha, each of the stored properties should hold these values and the description property should look like this:

"red: 86.0, green: 191.0, blue: 131.0, alpha: 1.0"

Note: Init methods typically list parameters in the same order of property declaration. For this task, stick to the order red,green,blue,alpha.

IT SAYS: " Bummer! The value of description does not match with the directions specified Preview "

MY CODE:

struct RGBColor { let red: Double let green: Double let blue: Double let alpha: Double

let description: String

// Add your code below

init(red: Double,green: Double, blue: Double, alpha: Double) {
    self.red = red 
    self.green = green 
    self.blue =  blue 
    self.alpha = alpha 
    self.description = ("red: \(red), green:\(green), blue:\(blue), alpha:\(alpha)")
}

}

RGBColor.init(red: 86.0, green: 191.0, blue: 131.0, alpha: 1.0)

What is wrong with my code?