Swift color creator for Google colors. https://material.google.com/style/color.html#color-color-palette

Colors.swift

//
//  Colors.swift
//  Uniview
//
//  Created by David James on 10/13/16.
//  Copyright © 2016 David B James. All rights reserved.
//

import UIKit

/**
 Colors based on Google Color Palette
 https://material.google.com/style/color.html#color-color-palette
 
 Shades are from lightest to darkest:
    50, 100, 200, 300, 400, 500, 600, 700, 800, 900
 
 All shades are prefixed with "s", e.g.:
    Color.red.s100
 
 Accents are available in:
    100, 200, 400, 700
 
 Accents are prefixed with "a", e.g.:
    Color.red.a700
 
 Mid-value is 500.
 
 Brown, Grey and BlueGrey do not have accents.
 
 Black, White and Clear are included for convenience.
 */
public enum Color:String, AccentedGoogleColor {
    
    case red = "Red"
    case pink = "Pink"
    case purple = "Purple"
    case deepPurple = "Deep Purple"
    case indigo = "Indigo"
    case blue = "Blue"
    case lightBlue = "Light Blue"
    case cyan = "Cyan"
    case teal = "Teal"
    case green = "Green"
    case lightGreen = "Light Green"
    case lime = "Lime"
    case yellow = "Yellow"
    case amber = "Amber"
    case orange = "Orange"
    case deepOrange = "Deep Orange"
    
    static var brown:Dull { return .brown }
    static var grey:Dull { return .grey }
    static var blueGrey:Dull { return .blueGrey }
    
    static var black:UIColor { return UIColor.black }
    static var white:UIColor { return UIColor.white }
    static var clear:UIColor { return UIColor.clear }
    
    /// This has to be public, but typically you would
    /// access these colors via the static vars:
    /// Color.brown.s300 etc (rather than Color.Dull.brown.s300)
    public enum Dull:String, GoogleColor {
        case brown = "Brown"
        case grey = "Grey"
        case blueGrey = "Blue Grey"
    }
}

protocol GoogleColor { }

extension GoogleColor where Self:RawRepresentable, Self.RawValue == String {
    
    var s50:UIColor { return make(shade: "50") }
    var s100:UIColor { return make(shade: "100") }
    var s200:UIColor { return make(shade: "200") }
    var s300:UIColor { return make(shade: "300") }
    var s400:UIColor { return make(shade: "400") }
    var s500:UIColor { return make(shade: "500") }
    var s600:UIColor { return make(shade: "600") }
    var s700:UIColor { return make(shade: "700") }
    var s800:UIColor { return make(shade: "800") }
    var s900:UIColor { return make(shade: "900") }
    
    func make(shade:String) -> UIColor {
        let colorName = self.rawValue
        return ColorStore.make(for: colorName, at: shade)
    }
}

protocol AccentedGoogleColor : GoogleColor { }

extension AccentedGoogleColor where Self:RawRepresentable, Self.RawValue == String {
    
    var a100:UIColor { return make(shade: "A100") }
    var a200:UIColor { return make(shade: "A200") }
    var a400:UIColor { return make(shade: "A400") }
    var a700:UIColor { return make(shade: "A700") }
}

/// Private store of hex colors matching Google's colors
fileprivate struct ColorStore {
    
    private static var colorCache:[String:UIColor] = [:]
    
    static func make(for color:String, at shade:String) -> UIColor {
        let key = "\(color)-\(shade)"
        if let color = colorCache[key] {
            return color
        } else {
            if let hexColor = rawColors[color]?[shade] {
                let color = UIColor(hexString: hexColor)
                colorCache[key] = color
                return color
            } else {
                // This should never happen because all colors in the store 
                // are represented in the enums above.
                print("🔥 WARNING: Color defaulting to black. Cannot find \(color) at shade \(shade).")
                return UIColor.black
            }
        }
    }
    
    private static let rawColors:[String:[String:String]] =
        ["Red":[
                "50":"ffebee", "100":"ffcdd2", "200":"ef9a9a", "300":"e57373", "400":"ef5350", "500":"f44336", "600":"e53935", "700":"d32f2f", "800":"c62828", "900":"b71c1c", "A100":"ff8a80", "A200":"ff5252", "A400":"ff1744", "A700":"d50000"
            ],
         "Pink":[
                "50":"fce4ec", "100":"f8bbd0", "200":"f48fb1", "300":"f06292", "400":"ec407a", "500":"e91e63", "600":"d81b60", "700":"c2185b", "800":"ad1457", "900":"880e4f", "A100":"ff80ab", "A200":"ff4081", "A400":"f50057", "A700":"c51162"
            ],
         "Purple":[
                "50":"f3e5f5", "100":"e1bee7", "200":"ce93d8", "300":"ba68c8", "400":"ab47bc", "500":"9c27b0", "600":"8e24aa", "700":"7b1fa2", "800":"6a1b9a", "900":"4a148c", "A100":"ea80fc", "A200":"e040fb", "A400":"d500f9", "A700":"aa00ff"
            ],
         "Deep Purple":[
                "50":"ede7f6", "100":"d1c4e9", "200":"b39ddb", "300":"9575cd", "400":"7e57c2", "500":"673ab7", "600":"5e35b1", "700":"512da8", "800":"4527a0", "900":"311b92", "A100":"b388ff", "A200":"7c4dff", "A400":"651fff", "A700":"6200ea"
            ],
         "Indigo":[
                "50":"e8eaf6", "100":"c5cae9", "200":"9fa8da", "300":"7986cb", "400":"5c6bc0", "500":"3f51b5", "600":"3949ab", "700":"303f9f", "800":"283593", "900":"1a237e", "A100":"8c9eff", "A200":"536dfe", "A400":"3d5afe", "A700":"304ffe"
            ],
         "Blue":[
                "50":"e3f2fd", "100":"bbdefb", "200":"90caf9", "300":"64b5f6", "400":"42a5f5", "500":"2196f3", "600":"1e88e5", "700":"1976d2", "800":"1565c0", "900":"0d47a1", "A100":"82b1ff", "A200":"448aff", "A400":"2979ff", "A700":"2962ff"
            ],
         "Light Blue":[
                "50":"e1f5fe", "100":"b3e5fc", "200":"81d4fa", "300":"4fc3f7", "400":"29b6f6", "500":"03a9f4", "600":"039be5", "700":"0288d1", "800":"0277bd", "900":"01579b", "A100":"80d8ff", "A200":"40c4ff", "A400":"00b0ff", "A700":"0091ea"
            ],
         "Cyan":[
                "50":"e0f7fa", "100":"b2ebf2", "200":"80deea", "300":"4dd0e1", "400":"26c6da", "500":"00bcd4", "600":"00acc1", "700":"0097a7", "800":"00838f", "900":"006064", "A100":"84ffff", "A200":"18ffff", "A400":"00e5ff", "A700":"00b8d4"
            ],
         "Teal":[
                "50":"e0f2f1", "100":"b2dfdb", "200":"80cbc4", "300":"4db6ac", "400":"26a69a", "500":"009688", "600":"00897b", "700":"00796b", "800":"00695c", "900":"004d40", "A100":"a7ffeb", "A200":"64ffda", "A400":"1de9b6", "A700":"00bfa5"
            ],
         "Green":[
                "50":"e8f5e9", "100":"c8e6c9", "200":"a5d6a7", "300":"81c784", "400":"66bb6a", "500":"4caf50", "600":"43a047", "700":"388e3c", "800":"2e7d32", "900":"1b5e20", "A100":"b9f6ca", "A200":"69f0ae", "A400":"00e676", "A700":"00c853"
            ],
         "Light Green":[
                "50":"f1f8e9", "100":"dcedc8", "200":"c5e1a5", "300":"aed581", "400":"9ccc65", "500":"8bc34a", "600":"7cb342", "700":"689f38", "800":"558b2f", "900":"33691e", "A100":"ccff90", "A200":"b2ff59", "A400":"76ff03", "A700":"64dd17"
            ],
         "Lime":[
                "50":"f9fbe7", "100":"f0f4c3", "200":"e6ee9c", "300":"dce775", "400":"d4e157", "500":"cddc39", "600":"c0ca33", "700":"afb42b", "800":"9e9d24", "900":"827717", "A100":"f4ff81", "A200":"eeff41", "A400":"c6ff00", "A700":"aeea00"
            ],
         "Yellow":[
                "50":"fffde7", "100":"fff9c4", "200":"fff59d", "300":"fff176", "400":"ffee58", "500":"ffeb3b", "600":"fdd835", "700":"fbc02d", "800":"f9a825", "900":"f57f17", "A100":"ffff8d", "A200":"ffff00", "A400":"ffea00", "A700":"ffd600"
            ],
         "Amber":[
                "50":"fff8e1", "100":"ffecb3", "200":"ffe082", "300":"ffd54f", "400":"ffca28", "500":"ffc107", "600":"ffb300", "700":"ffa000", "800":"ff8f00", "900":"ff6f00", "A100":"ffe57f", "A200":"ffd740", "A400":"ffc400", "A700":"ffab00"
            ],
         "Orange":[
                "50":"fff3e0", "100":"ffe0b2", "200":"ffcc80", "300":"ffb74d", "400":"ffa726", "500":"ff9800", "600":"fb8c00", "700":"f57c00", "800":"ef6c00", "900":"e65100", "A100":"ffd180", "A200":"ffab40", "A400":"ff9100", "A700":"ff6d00"
            ],
         "Deep Orange":[
                "50":"fbe9e7", "100":"ffccbc", "200":"ffab91", "300":"ff8a65", "400":"ff7043", "500":"ff5722", "600":"f4511e", "700":"e64a19", "800":"d84315", "900":"bf360c", "A100":"ff9e80", "A200":"ff6e40", "A400":"ff3d00", "A700":"dd2c00"
            ],
         "Brown":[
                "50":"efebe9", "100":"d7ccc8", "200":"bcaaa4", "300":"a1887f", "400":"8d6e63", "500":"795548", "600":"6d4c41", "700":"5d4037", "800":"4e342e", "900":"3e2723"
            ],
         "Grey":[
                "50":"fafafa", "100":"f5f5f5", "200":"eeeeee", "300":"e0e0e0", "400":"bdbdbd", "500":"9e9e9e", "600":"757575", "700":"616161", "800":"424242", "900":"212121"
            ],
         "Blue Grey":[
                "50":"eceff1", "100":"cfd8dc", "200":"b0bec5", "300":"90a4ae", "400":"78909c", "500":"607d8b", "600":"546e7a", "700":"455a64", "800":"37474f", "900":"263238"
            ]
    ]
}

ColorsExample.swift

Color.clear
Color.blueGrey.s300 // NOTE: Color.blueGrey.a100 is not possible
Color.green.s500
Color.red.a700

UIColor+Helpers.swift

//
//  UIColor+Helpers.swift
//  Uniview
//
//  Created by David James on 10/13/16.
//  Copyright © 2016 David B James. All rights reserved.
//

import UIKit

extension UIColor {
    /// Create a UIColor based on 0-255 ranges of RGB colors
    convenience init(red: Int, green: Int, blue: Int) {
        assert(red >= 0 && red <= 255, "Invalid red component")
        assert(green >= 0 && green <= 255, "Invalid green component")
        assert(blue >= 0 && blue <= 255, "Invalid blue component")
        
        self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: 1.0)
    }
    
    /// Create a UIColor based on an integer (representing hex)
    convenience init(hex:Int) {
        self.init(red:(hex >> 16) & 0xff, green:(hex >> 8) & 0xff, blue:hex & 0xff)
    }
    
    /// Create a UIColor based on a string (representing hex)
    convenience init(hexString:String) {
        self.init(hex:Int(hexString, radix:16)!)
    }
}