fix: update welcome sign-up button appearance and override welcome scene to light style

Mastodon/Generated/Assets.swift

@@ -91,6 +91,7 @@ internal enum Asset {
     }
     internal static let battleshipGrey = ColorAsset(name: "Colors/battleshipGrey")
     internal static let brandBlue = ColorAsset(name: "Colors/brand.blue")
+    internal static let brandBlueDarken20 = ColorAsset(name: "Colors/brand.blue.darken.20")
     internal static let danger = ColorAsset(name: "Colors/danger")
     internal static let disabled = ColorAsset(name: "Colors/disabled")
     internal static let inactive = ColorAsset(name: "Colors/inactive")

Mastodon/Resources/Assets.xcassets/Colors/brand.blue.darken.20.colorset/Contents.json

@@ -0,0 +1,38 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0xB0",
+          "green" : "0x73",
+          "red" : "0x1F"
+        }
+      },
+      "idiom" : "universal"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0xC9",
+          "green" : "0x80",
+          "red" : "0x1B"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

Mastodon/Scene/Onboarding/Welcome/WelcomeViewController.swift

@@ -37,9 +37,10 @@ final class WelcomeViewController: UIViewController, NeedsDependency {
     private(set) lazy var  signUpButton: PrimaryActionButton = {
         let button = PrimaryActionButton()
         button.setTitle(L10n.Common.Controls.Actions.signUp, for: .normal)
-        let backgroundImageColor: UIColor = traitCollection.userInterfaceIdiom == .phone ? .white : Asset.Colors.Button.normal.color
+        let backgroundImageColor: UIColor = traitCollection.userInterfaceIdiom == .phone ? .white : Asset.Colors.brandBlue.color
+        let backgroundImageHighlightedColor: UIColor = traitCollection.userInterfaceIdiom == .phone ? UIColor(white: 0.8, alpha: 1.0) : Asset.Colors.brandBlueDarken20.color
         button.setBackgroundImage(.placeholder(color: backgroundImageColor), for: .normal)
-        button.setBackgroundImage(.placeholder(color: backgroundImageColor.withAlphaComponent(0.9)), for: .highlighted)
+        button.setBackgroundImage(.placeholder(color: backgroundImageHighlightedColor), for: .highlighted)
         let titleColor: UIColor = traitCollection.userInterfaceIdiom == .phone ? Asset.Colors.Button.normal.color : UIColor.white
         button.setTitleColor(titleColor, for: .normal)
         button.translatesAutoresizingMaskIntoConstraints = false
@@ -67,6 +68,8 @@ extension WelcomeViewController {
     override func viewDidLoad() {
         super.viewDidLoad()
         
+        view.overrideUserInterfaceStyle = .light
+        
         setupOnboardingAppearance()
         setupIllustrationLayout()