Help with the Code Challenge??

I know this code is not what the task is asking for but I forgot/don't know how to create a value for the description property that is a string representation of the color object? I just don't understand what it wants me to do. Any help would be great thanks!

// 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.

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, description: String) {
    self.red = red
    self.green = green
    self.blue = blue
    self.alpha = alpha
    self.description = description
}
func printColorValues() -> String {
    let description = "red: \(red), green: \(green), blue: \(blue), alpha: \(alpha)"
    return description
}

} let aColorList = RGBColor(red: 86.0, green: 191.0, blue: 131.0, alpha: 1.0, description: "Blah") let asdfjskd = aColorList.printColorValues()

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, description: String) {
        self.red = red
        self.green = green
        self.blue = blue
        self.alpha = alpha
        self.description = description
    }
    func printColorValues() -> String {
        let description = "red: \(red), green: \(green), blue: \(blue), alpha: \(alpha)"
        return description
    }
}
let aColorList = RGBColor(red: 86.0, green: 191.0, blue: 131.0, alpha: 1.0, description: "Blah")
let asdfjskd = aColorList.printColorValues()