Add a color picker to an iOS app

Question

I'm trying to add a color picker to my iOS application, using Xcode 5. It appears that Xcode offers a color well via the Palettes Panel of Interface Builder, but I can't find the Palettes Panel (nor can I find any documentation of it online beyond that link).

That link also suggests an NSColorWell can be added programatically. I'd prefer to go the Interface Builder route, but if that's not an option sample code would be welcome.

Answer 1

I had the same question as you. It's unfortunate that there is no built in color picker for iOS. The other answers here and for similar questions mainly use third party libraries or projects. I prefer to avoid all the third party stuff whenever possible, so that leaves us with...

Make your own color picker

There are many ways you could do it, but here is a simple example to show the concept. I set up my story board like this:

It has a UIView (grey here) to show the chosen color, a UIImageView to show the color choices, and a UISlider to choose the color. I used the following image in the UIImageView:

I made it from the colors of a 12-spoke color wheel using a screen shot and Gimp's color picker tool. Gimp is also useful for getting the color hex codes we will use later.

Set the min and max values for the Slider to 0.5 and 13.5. Converting the slider values to integers later will give one number for each of the colors in our image. Starting at 0.5 rather than 0 makes the slider color change location match the image better.

Hook up the UI elements to the View Controller and use the following code to convert the slider position to colors.

class ViewController: UIViewController {
 
    // RRGGBB hex colors in the same order as the image
    let colorArray = [ 0x000000, 0xfe0000, 0xff7900, 0xffb900, 0xffde00, 0xfcff00, 0xd2ff00, 0x05c000, 0x00c0a7, 0x0600ff, 0x6700bf, 0x9500c0, 0xbf0199, 0xffffff ]
    
    @IBOutlet weak var selectedColorView: UIView!
    @IBOutlet weak var slider: UISlider!
    @IBAction func sliderChanged(sender: AnyObject) {
        selectedColorView.backgroundColor = uiColorFromHex(colorArray[Int(slider.value)])
    }
   
    func uiColorFromHex(rgbValue: Int) -> UIColor {
        
        let red =   CGFloat((rgbValue & 0xFF0000) >> 16) / 0xFF
        let green = CGFloat((rgbValue & 0x00FF00) >> 8) / 0xFF
        let blue =  CGFloat(rgbValue & 0x0000FF) / 0xFF
        let alpha = CGFloat(1.0)
        
        return UIColor(red: red, green: green, blue: blue, alpha: alpha)
    }
}

Now if you run it, you can choose the color by moving the slider back and forth.

Variations

• Position the slider on top of the image and set the track tints to transparent. This gives it the feel of a custom UI without having to subclass anything.

• Here is another image with lighter and darker variations of the example project image.

let colorArray = [ 0x000000, 0x262626, 0x4d4d4d, 0x666666, 0x808080, 0x990000, 0xcc0000, 0xfe0000, 0xff5757, 0xffabab, 0xffabab, 0xffa757, 0xff7900, 0xcc6100, 0x994900, 0x996f00, 0xcc9400, 0xffb900, 0xffd157, 0xffe8ab, 0xfff4ab, 0xffe957, 0xffde00, 0xccb200, 0x998500, 0x979900, 0xcacc00, 0xfcff00, 0xfdff57, 0xfeffab, 0xf0ffab, 0xe1ff57, 0xd2ff00, 0xa8cc00, 0x7e9900, 0x038001, 0x04a101, 0x05c001, 0x44bf41, 0x81bf80, 0x81c0b8, 0x41c0af, 0x00c0a7, 0x00a18c, 0x00806f, 0x040099, 0x0500cc, 0x0600ff, 0x5b57ff, 0xadabff, 0xd8abff, 0xb157ff, 0x6700bf, 0x5700a1, 0x450080, 0x630080, 0x7d00a1, 0x9500c0, 0xa341bf, 0xb180bf, 0xbf80b2, 0xbf41a6, 0xbf0199, 0xa10181, 0x800166, 0x999999, 0xb3b3b3, 0xcccccc, 0xe6e6e6, 0xffffff]

• Use an array of UIColors to avoid having to do the hex conversion.

• Could use multiple UIViews rather than an image, and then set the colors directly from the array.

Further study

• Color Theory For Designers, Part 2: Understanding Concepts And Terminology
• Color Theory For Designers: Creating Your Own Color Palettes
• Simple swift color picker popover (iOS)