Dark-mode compatible UIColor extension with Objective-C

UIColor+Ext.h

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface UIColor (Ext)

// Original Colors
+ (UIColor *) primary;

// Compatible System Colors for iOS 12 and below
+ (UIColor *) label;
+ (UIColor *) secondaryLabel;
+ (UIColor *) tertiaryLabel;
+ (UIColor *) quaternaryLabel;
+ (UIColor *) systemFill;
+ (UIColor *) secondarySystemFill;
+ (UIColor *) tertiarySystemFill;
+ (UIColor *) quaternarySystemFill;
+ (UIColor *) placeholderText;
+ (UIColor *) systemBackground;
+ (UIColor *) secondarySystemBackground;
+ (UIColor *) tertiarySystemBackground;
+ (UIColor *) systemGroupedBackground;
+ (UIColor *) secondarySystemGroupedBackground;
+ (UIColor *) tertiarySystemGroupedBackground;
+ (UIColor *) separator;
+ (UIColor *) opaqueSeparator;
+ (UIColor *) link;
+ (UIColor *) darkText;
+ (UIColor *) lightText;
+ (UIColor *) systemBlue;
+ (UIColor *) systemGreen;
+ (UIColor *) systemIndigo;
+ (UIColor *) systemOrange;
+ (UIColor *) systemPink;
+ (UIColor *) systemPurple;
+ (UIColor *) systemRed;
+ (UIColor *) systemTeal;
+ (UIColor *) systemYellow;
+ (UIColor *) systemGray;
+ (UIColor *) systemGray2;
+ (UIColor *) systemGray3;
+ (UIColor *) systemGray4;
+ (UIColor *) systemGray5;
+ (UIColor *) systemGray6;

@end

NS_ASSUME_NONNULL_END

UIColor+Ext.m

#import "UIColor+Ext.h"

@implementation UIColor (Ext)

+ (UIColor *) primary {
    return [UIColor colorNamed:@"Primary"];
}

+ (UIColor *) label {
    if (@available(iOS 13, *)) {
        return UIColor.labelColor;
    } else {
        return UIColor.blackColor;
    }
}

+ (UIColor *) secondaryLabel {
    if (@available(iOS 13, *)) {
        return UIColor.secondaryLabelColor;
    } else {
        return [UIColor colorWithRed:60.0/255 green:60.0/255 blue:67.0/255 alpha:0.6];
    }
}

+ (UIColor *) tertiaryLabel {
    if (@available(iOS 13, *)) {
        return UIColor.tertiaryLabelColor;
    } else {
        return [UIColor colorWithRed:60.0/255 green:60.0/255 blue:67.0/255 alpha:0.3];
    }
}

+ (UIColor *) quaternaryLabel {
    if (@available(iOS 13, *)) {
        return UIColor.quaternaryLabelColor;
    } else {
        return [UIColor colorWithRed:60.0/255 green:60.0/255 blue:67.0/255 alpha:0.18];
    }
}

+ (UIColor *) systemFill {
    if (@available(iOS 13, *)) {
        return UIColor.systemFillColor;
    } else {
        return [UIColor colorWithRed:120.0/255 green:120.0/255 blue:128.0/255 alpha:0.2];
    }
}

+ (UIColor *) secondarySystemFill {
    if (@available(iOS 13, *)) {
        return UIColor.secondarySystemFillColor;
    } else {
        return [UIColor colorWithRed:120.0/255 green:120.0/255 blue:128.0/255 alpha:0.16];
    }
}

+ (UIColor *) tertiarySystemFill {
    if (@available(iOS 13, *)) {
        return UIColor.tertiarySystemFillColor;
    } else {
        return [UIColor colorWithRed:118.0/255 green:118.0/255 blue:128.0/255 alpha:0.12];
    }
}

+ (UIColor *) quaternarySystemFill {
    if (@available(iOS 13, *)) {
        return UIColor.quaternarySystemFillColor;
    } else {
        return [UIColor colorWithRed:116.0/255 green:116.0/255 blue:128.0/255 alpha:0.08];
    }
}

+ (UIColor *) placeholderText {
    if (@available(iOS 13, *)) {
        return UIColor.placeholderTextColor;
    } else {
        return [UIColor colorWithRed:60.0/255 green:60.0/255 blue:67.0/255 alpha:0.3];
    }
}

+ (UIColor *) systemBackground {
    if (@available(iOS 13, *)) {
        return UIColor.systemBackgroundColor;
    } else {
        return UIColor.whiteColor;
    }
}

+ (UIColor *) secondarySystemBackground {
    if (@available(iOS 13, *)) {
        return UIColor.secondarySystemBackgroundColor;
    } else {
        return [UIColor colorWithRed:242.0/255 green:242.0/255 blue:247.0/255 alpha:1.0];
    }
}

+ (UIColor *) tertiarySystemBackground {
    if (@available(iOS 13, *)) {
        return UIColor.tertiarySystemBackgroundColor;
    } else {
        return [UIColor colorWithRed:255.0/255 green:255.0/255 blue:255.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemGroupedBackground {
    if (@available(iOS 13, *)) {
        return UIColor.systemGroupedBackgroundColor;
    } else {
        return [UIColor colorWithRed:242.0/255 green:242.0/255 blue:247.0/255 alpha:1.0];
    }
}

+ (UIColor *) secondarySystemGroupedBackground {
    if (@available(iOS 13, *)) {
        return UIColor.secondarySystemGroupedBackgroundColor;
    } else {
        return [UIColor colorWithRed:255.0/255 green:255.0/255 blue:255.0/255 alpha:1.0];
    }
}

+ (UIColor *) tertiarySystemGroupedBackground {
    if (@available(iOS 13, *)) {
        return UIColor.tertiarySystemGroupedBackgroundColor;
    } else {
        return [UIColor colorWithRed:242.0/255 green:242.0/255 blue:247.0/255 alpha:1.0];
    }
}

+ (UIColor *) separator {
    if (@available(iOS 13, *)) {
        return UIColor.separatorColor;
    } else {
        return [UIColor colorWithRed:60.0/255 green:60.0/255 blue:67.0/255 alpha:0.29];
    }
}

+ (UIColor *) opaqueSeparator {
    if (@available(iOS 13, *)) {
        return UIColor.opaqueSeparatorColor;
    } else {
        return [UIColor colorWithRed:198.0/255 green:198.0/255 blue:200.0/255 alpha:1.0];
    }
}

+ (UIColor *) link {
    if (@available(iOS 13, *)) {
        return UIColor.linkColor;
    } else {
        return [UIColor colorWithRed:0.0/255 green:122.0/255 blue:255.0/255 alpha:1.0];
    }
}

+ (UIColor *) darkText {
    if (@available(iOS 13, *)) {
        return UIColor.darkTextColor;
    } else {
        return [UIColor colorWithRed:0.0/255 green:0.0/255 blue:0.0/255 alpha:1.0];
    }
}

+ (UIColor *) lightText {
    if (@available(iOS 13, *)) {
        return UIColor.lightTextColor;
    } else {
        return [UIColor colorWithRed:255.0/255 green:255.0/255 blue:255.0/255 alpha:0.6];
    }
}

+ (UIColor *) systemBlue {
    if (@available(iOS 13, *)) {
        return UIColor.systemBlueColor;
    } else {
        return [UIColor colorWithRed:0.0/255 green:122.0/255 blue:255.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemGreen {
    if (@available(iOS 13, *)) {
        return UIColor.systemGreenColor;
    } else {
        return [UIColor colorWithRed:52.0/255 green:199.0/255 blue:89.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemIndigo {
    if (@available(iOS 13, *)) {
        return UIColor.systemBlueColor;
    } else {
        return [UIColor colorWithRed:88.0/255 green:86.0/255 blue:214.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemOrange {
    if (@available(iOS 13, *)) {
        return UIColor.systemOrangeColor;
    } else {
        return [UIColor colorWithRed:255.0/255 green:149.0/255 blue:0.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemPink {
    if (@available(iOS 13, *)) {
        return UIColor.systemPinkColor;
    } else {
        return [UIColor colorWithRed:255.0/255 green:45.0/255 blue:85.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemPurple {
    if (@available(iOS 13, *)) {
        return UIColor.systemPurpleColor;
    } else {
        return [UIColor colorWithRed:175.0/255 green:82.0/255 blue:222.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemRed {
    if (@available(iOS 13, *)) {
        return UIColor.systemRedColor;
    } else {
        return [UIColor colorWithRed:255.0/255 green:59.0/255 blue:48.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemTeal {
    if (@available(iOS 13, *)) {
        return UIColor.systemTealColor;
    } else {
        return [UIColor colorWithRed:90.0/255 green:200.0/255 blue:250.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemYellow {
    if (@available(iOS 13, *)) {
        return UIColor.systemYellowColor;
    } else {
        return [UIColor colorWithRed:255.0/255 green:204.0/255 blue:0.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemGray {
    if (@available(iOS 13, *)) {
        return UIColor.systemGrayColor;
    } else {
        return [UIColor colorWithRed:142.0/255 green:142.0/255 blue:147.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemGray2 {
    if (@available(iOS 13, *)) {
        return UIColor.systemGray2Color;
    } else {
        return [UIColor colorWithRed:174.0/255 green:174.0/255 blue:178.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemGray3 {
    if (@available(iOS 13, *)) {
        return UIColor.systemGray3Color;
    } else {
        return [UIColor colorWithRed:72.0/255 green:72.0/255 blue:74.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemGray4 {
    if (@available(iOS 13, *)) {
        return UIColor.systemGray4Color;
    } else {
        return [UIColor colorWithRed:58.0/255 green:58.0/255 blue:60.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemGray5 {
    if (@available(iOS 13, *)) {
        return UIColor.systemGray5Color;
    } else {
        return [UIColor colorWithRed:44.0/255 green:44.0/255 blue:46.0/255 alpha:1.0];
    }
}

+ (UIColor *) systemGray6 {
    if (@available(iOS 13, *)) {
        return UIColor.systemGray6Color;
    } else {
        return [UIColor colorWithRed:28.0/255 green:28.0/255 blue:30.0/255 alpha:1.0];
    }
}

@end