CostumeKit :tophat:

Base types for theming an app.

CostumeKit is made of up a set of Swift protocols. They are meant to be implemented by you in your app.

Featured in Little Bites of Cocoa Bite #270: Implementing Theming with CostumeKit

Color :art:

Includes Color and ColorPalette protocols.


public enum MyAppColors : Color, ColorPalette {
  case white = "FFFFFF"
  case lightTeal = "3CB39E"
  case forestGreen = "216055"
  case black = "000000"

Font :capital_abcd:

Includes Font protocol, and one concrete SystemFont implementation for iOS system fonts.


public struct MyAppFont : Font {
  public init(size: FontSize = .textStyle(.body)) {
    self.size = size

  // Font

  public var size: FontSize

  // FontConvertible

  public var FontValue: UIFont {
    return UIFont(name: "SomeCustomFont", size: pointSize)!

SVG :stars:

Includes SVG Protocol and SVGMetadata type.


enum MyAppSVGs {
  case clockGlyph
  case bird

extension MyAppSVGs : SVG {
  public func metadata() -> SVGMetadata {
    switch self {
      case .clockGlyph: return SVGMetadata(name: "clock", size: CGSize(width: 100, height: 100), fullColor: false)
      case .bird: return SVGMetadata(name: "bird", size: CGSize(width: 58, height: 28), fullColor: true)

What you do with SVGMetadata is up to you. I recommend SwiftSVG from Michael Choe. Read more here to learn how to use it.

CostumeKit's goals are to be a generic solution, so no assumptions are made about how something should be retrieved from disk, parsed, etc. You'll need to implement these anyways, so nothing is forced on you.

Costume :tophat:

Includes Costume protocol. Usage:

open class MyAppCostume : Costume {
  let spacing = CGFloat(8)

  public func wearRootBackground(_ view: UIView) {
    view.backgroundColor =

  public func wearHeadline(_ label: UILabel) {
    label.font = MyAppFont(size: .textStyle(.title1)).fontValue
    label.textColor = MyAppColors.forestGreen.colorValue

  public var name: String { return "Default" }
  public var description: String { return "The default costume." }

  public init() { }