iOS Cgcolor Versus Uicolor

CGColor to UIColor conversion

Thats because that CGColor initializer uses a different color space. UIColor uses extendedSRGB while CGColor uses Generic RGB.

If you want to get the same color you need to specify the same colorspace when initializing your CGColor:

let cgColor = CGColor(colorSpace: .init(name: CGColorSpace.extendedSRGB)!, components: [19.0/255, 25.0/255, 28.0/255, 1.0])!

For iOS13+ or macOS10.15+ you can use the init(srgbRed:green:blue:alpha:) initializer:

let cgColor = CGColor(srgbRed: 19/255, green: 25/255, blue: 28/255, alpha: 1)

Odd Conversion between UIColor and CGColor

You need to divide the parameters by 255.0. As noted by @Duncan C, ensure you are dividing by 255.0

[[UIColor colorWithRed:202.0/255.0 green:0 blue:11/255.0 alpha:1] CGColor]

[[UIColor colorWithRed:0 green:19/255.0 blue:133/255.0 alpha:1] CGColor]

Wrong color when convert UIColor to CGColor

Colors in UIKit are specified using value is between 0 and 1 in float not int from 0 to 255, so you need to divide all your RGB values by 255.0.

let color = UIColor(red: 198.0/255.0, green: 35.0/255.0, blue: 80.0/255.0, alpha: 1.0)

IOS/Objective-C: Convert standard UIColor to CGColor

You can't save UIColor object in NSUserDefaults directly.

try to archive object to get data and save the data like this:

UIColor *color = [UIColor redColor];
NSData *colorData = [NSKeyedArchiver archivedDataWithRootObject:color];
[[NSUserDefaults standardUserDefaults] setObject:colorData forKey:@"ColorKey"];

And when you need the color firstly you should get NSData object from User Defaults and then create UIColor object like this

NSData *colorData = [[NSUserDefaults standardUserDefaults] objectForKey:@"ColorKey"];
UIColor *color = [NSKeyedUnarchiver unarchiveObjectWithData:colorData];

Converting UIColor to CGColor in swift

// Original answer.
var newColor = UIColor.lightGrayColor().CGColor

// Swift 3 version
var newColor = UIColor.lightGray.cgColor

How to convert UIColor to SwiftUI‘s Color

Starting with beta 5, you can create a Color from a UIColor:

Color(UIColor.systemBlue)