Fix color mismatch on ui compacibility test case

Author: Kyle-Ye

Example/OpenSwiftUIUITests/Layout/Stack/ZStackUITests.swift

@@ -87,9 +87,7 @@ struct ZStackUITests {
             }
         }
         openSwiftUIAssertSnapshot(
-            of: ContentView(),
-            // FIXME: Workaround #340
-            perceptualPrecision: 0.99
+            of: ContentView()
         )
     }
 }

Example/OpenSwiftUIUITests/UITests/Initialize.c

@@ -0,0 +1,15 @@
+//
+//  Initialize.c
+//  OpenSwiftUIUITests
+//
+//  Created by Kyle on 12/29/25.
+//
+
+#include "Initialize.h"
+#include <stdio.h>
+
+static void OpenSwiftUIUITests_InitializeSwift(void);
+
+static void OpenSwiftUIUITests_Initialize(void) {
+    OpenSwiftUIUITests_InitializeSwift();
+}

Example/OpenSwiftUIUITests/UITests/Initialize.h

@@ -0,0 +1,11 @@
+//
+//  Initialize.h
+//  OpenSwiftUIUITests
+//
+//  Created by Kyle on 12/29/25.
+//
+
+#pragma once
+
+__attribute__((constructor, used))
+static void OpenSwiftUIUITests_Initialize(void);

Example/OpenSwiftUIUITests/UITests/Initialize.swift

@@ -0,0 +1,18 @@
+//
+//  Initialize.swift
+//  OpenSwiftUIUITests
+//
+//  Created by Kyle on 12/29/25.
+//
+
+#if OPENSWIFTUI
+@_spi(ForTestOnly)
+import OpenSwiftUI
+#endif
+
+@_cdecl("OpenSwiftUIUITests_InitializeSwift")
+func __initialize() -> () {
+    #if OPENSWIFTUI
+    Color.Resolved._alignWithSwiftUIImplementation = true
+    #endif
+}