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Extracting RGB values from UIColor

  • Jun 21, 2017

This code snippet is an extension to the UIColor class for extractiog the RGB color values since accessing theme with the built in methods is messy.

This is the code, you can insert it into any of the project files:

extension UIColor {

    public func rgb() -> (red:Int, green:Int, blue:Int, alpha:Int)? {
        var fRed : CGFloat = 0
        var fGreen : CGFloat = 0
        var fBlue : CGFloat = 0
        var fAlpha: CGFloat = 0
        if self.getRed(&fRed, green: &fGreen, blue: &fBlue, alpha: &fAlpha) {
            let iRed = Int(fRed)
            let iGreen = Int(fGreen)
            let iBlue = Int(fBlue)
            let iAlpha = Int(fAlpha)

            return (red:iRed, green:iGreen, blue:iBlue, alpha:iAlpha)
        } else {
            // Could not extract RGBA components:
            return nil
        }
    }
}

Now how to use this extension

  1. You need to import UIKit…. duh…

    import UIKit

  2. Create an instance of the UIColor class

      let color: UIColor = UIColor(red: 234, green: 54, blue: 1, alpha: 1)

  3. Call the rgb() method

      let rgb = color.rgb()

  4. Now you can access each color, they are returned in Int?

      let red = color.rgb()?.red
  let green = color.rgb()?.green
  let blue = color.rgb()?.blue
  let alpha = color.rgb()?.alpha

  5. If you want to print theme than you can wrap theme up in a neat String

      let rgbColors = "R:\(red!) G:\(green!) B:\(blue!) A:\(alpha!)"
  print(rgbColors)

Full playground file:

import UIKit

extension UIColor {

    public func rgb() -> (red:Int, green:Int, blue:Int, alpha:Int)? {
        var fRed : CGFloat = 0
        var fGreen : CGFloat = 0
        var fBlue : CGFloat = 0
        var fAlpha: CGFloat = 0
        if self.getRed(&fRed, green: &fGreen, blue: &fBlue, alpha: &fAlpha) {
            let iRed = Int(fRed)
            let iGreen = Int(fGreen)
            let iBlue = Int(fBlue)
            let iAlpha = Int(fAlpha)

            return (red:iRed, green:iGreen, blue:iBlue, alpha:iAlpha)
        } else {
            // Could not extract RGBA components:
            return nil
        }
    }
}

let color: UIColor = UIColor(red: 234, green: 54, blue: 1, alpha: 1)

let rgb = color.rgb()

let red = color.rgb()?.red //
let green = color.rgb()?.green
let blue = color.rgb()?.blue
let alph = color.rgb()?.alpha

let rgbColors = "R:\(red!) G:\(green!) B:\(blue!) A:\(alpha!)"
print(rgbColors)

If you have any questions or taughts leave theme down below in the comment section.

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