This project allows you to create Xcode Assets catalogs for your colors. Instead of tediously creating your named colors in Xcode's UI you can create a CSS-like document and have your Asset catalog generated programmatically. Specify colors in hex (with a twist, to allow specifying the alpha value in percent) and RGBA. Use variables for your colors and support dark mode. Finally, generate a corresponding Swift file to reference the created colors safely in your code.
Since version 0.4.0 it is also possible to generate a Swift file which does not depend on Asset catalogs and uses dynamic colors instead. This solves a problem where Asset Catalogs would not be compiled correctly in the Xcode 11 beta 6/7 and accessing colors at runtime did not work on iOS < 13. See below an example of the generated code.
// Basic colors
$white: #ffffff
$black: #000000
$black50: #000000 50%
$classic: (light: $black, dark: $white)
// Accent colors
$brightAccent: #5753CF
$mediumBright: rgba(25, 200, 255, 1)
$mediumBrightHighlight: #70D1FA
// Greys
$grey1: $black
// Declarations
Text {
Primary: (light: #151618, dark: #E7E8EA)
Secondary: (light: $grey1, dark: #85868A)
}
LightContentSeparator: (light: #F1F2F2, dark: #222525)
NumericInput {
NumericKey {
Background: (light: $white, dark: #434343)
Highlight: (light: #C4CCDA, dark: #666666)
Shadow: (light: #848587, dark: $black50 50%) // Apply alpha to variables
Text: $classic
}
DoneKey {
Background: (light: $mediumBright, dark: $brightAccent)
Highlight: (light: $mediumBrightHighlight, dark: rgba(103, 122, 219, 1))
Shadow: (light: #6E7073, dark: $black)
Text: $classic
}
Background: (light: #D6D9DE 30%, dark: #313131 40%)
}
$ xcode-color-assets gen-assets colors.assetstyles -o Colors.xcassets --color-space srgb
$ xcode-color-assets gen-swift colors.assetstyles -o UIColor+Custom.swift --mode asset-catalog
// This file is automatically generated. Do not edit, your changes will be erased.
import UIKit
extension UIColor {
enum Custom {
static let LightContentSeparator = UIColor(named: "LightContentSeparator")!
enum NumericInput {
enum NumericKey {
static let Background = UIColor(named: "NumericInputNumericKeyBackground")!
static let Highlight = UIColor(named: "NumericInputNumericKeyHighlight")!
static let Shadow = UIColor(named: "NumericInputNumericKeyShadow")!
static let Text = UIColor(named: "NumericInputNumericKeyText")!
}
enum DoneKey {
static let Background = UIColor(named: "NumericInputDoneKeyBackground")!
static let Highlight = UIColor(named: "NumericInputDoneKeyHighlight")!
static let Shadow = UIColor(named: "NumericInputDoneKeyShadow")!
static let Text = UIColor(named: "NumericInputDoneKeyText")!
}
static let Background = UIColor(named: "NumericInputBackground")!
}
enum Text {
static let Primary = UIColor(named: "TextPrimary")!
static let Secondary = UIColor(named: "TextSecondary")!
}
}
}$ xcode-color-assets gen-swift colors.assetstyles -o UIColor+Custom.swift --mode dynamic-color
// This file is automatically generated. Do not edit, your changes will be erased.
import UIKit
private struct ColorSet {
var light: UIColor
var dark: UIColor?
init(_ light: UIColor, _ dark: UIColor?) {
self.light = light
self.dark = dark
}
}
private func dynamicColor(_ colorSet: ColorSet) -> UIColor {
if #available(iOS 13.0, *) {
return UIColor { traits -> UIColor in
switch traits.userInterfaceStyle {
case .dark:
return colorSet.dark ?? colorSet.light
case .light, .unspecified:
fallthrough
@unknown default:
return colorSet.light
}
}
} else {
return colorSet.light
}
}
private let ColorSets: [ColorSet] = [
ColorSet(UIColor(red: 0.945, green: 0.949, blue: 0.949, alpha: 1.00), UIColor(red: 0.133, green: 0.145, blue: 0.145, alpha: 1.00)),
ColorSet(UIColor(red: 0.839, green: 0.851, blue: 0.871, alpha: 0.30), UIColor(red: 0.192, green: 0.192, blue: 0.192, alpha: 0.40)),
ColorSet(UIColor(red: 0.098, green: 0.784, blue: 1.000, alpha: 1.00), UIColor(red: 0.341, green: 0.325, blue: 0.812, alpha: 1.00)),
ColorSet(UIColor(red: 0.439, green: 0.820, blue: 0.980, alpha: 1.00), UIColor(red: 0.404, green: 0.478, blue: 0.859, alpha: 1.00)),
ColorSet(UIColor(red: 0.431, green: 0.439, blue: 0.451, alpha: 1.00), nil),
ColorSet(UIColor(red: 0.000, green: 0.000, blue: 0.000, alpha: 1.00), UIColor(red: 1.000, green: 1.000, blue: 1.000, alpha: 1.00)),
ColorSet(UIColor(red: 1.000, green: 1.000, blue: 1.000, alpha: 1.00), UIColor(red: 0.263, green: 0.263, blue: 0.263, alpha: 1.00)),
ColorSet(UIColor(red: 0.769, green: 0.800, blue: 0.855, alpha: 1.00), UIColor(red: 0.400, green: 0.400, blue: 0.400, alpha: 1.00)),
ColorSet(UIColor(red: 0.518, green: 0.522, blue: 0.529, alpha: 1.00), UIColor(red: 0.000, green: 0.000, blue: 0.000, alpha: 1.00)),
ColorSet(UIColor(red: 0.082, green: 0.086, blue: 0.094, alpha: 1.00), UIColor(red: 0.906, green: 0.910, blue: 0.918, alpha: 1.00)),
ColorSet(UIColor(red: 0.000, green: 0.000, blue: 0.000, alpha: 1.00), UIColor(red: 0.522, green: 0.525, blue: 0.541, alpha: 1.00)),
]
extension UIColor {
enum Custom {
static let LightContentSeparator = dynamicColor(ColorSets[0])
enum NumericInput {
static let Background = dynamicColor(ColorSets[1])
enum DoneKey {
static let Background = dynamicColor(ColorSets[2])
static let Highlight = dynamicColor(ColorSets[3])
static let Shadow = dynamicColor(ColorSets[4])
static let Text = dynamicColor(ColorSets[5])
}
enum NumericKey {
static let Background = dynamicColor(ColorSets[6])
static let Highlight = dynamicColor(ColorSets[7])
static let Shadow = dynamicColor(ColorSets[8])
static let Text = dynamicColor(ColorSets[5])
}
}
enum Text {
static let Primary = dynamicColor(ColorSets[9])
static let Secondary = dynamicColor(ColorSets[10])
}
}
}$ brew install nesium/tools/xcode-color-assets
By using FSWatch you can observe your stylesheet for changes and have the Asset Catalog and Swift file generated automatically. See a Makefile example below.
watch_colors:
@fswatch -o Color_Assets/colors.assetstyles | (while read; do make colors; done)
colors:
@xcode-color-assets gen-assets Color_Assets/colors.assetstyles -o Colors.xcassets --force --color-space srgb
@xcode-color-assets gen-swift Color_Assets/colors.assetstyles -o ../Shared/Colors.swift --mode asset-catalog