Hey there, let's break down this tricky issue you're facing—since you can't outline every intermediate operation right now, I'll focus on the most likely culprits and fixes based on your scenario:

• Accidental modification of the original Prefab asset
  It's easy to slip up and edit the original Prefab instead of its runtime instance, especially in beta builds where asset caching might behave unpredictably. For example, if your code looks like this (which modifies the actual asset):

  // ❌ Wrong: Alters the original Prefab in your project
  var prefabA = Resources.Load<GameObject>("PrefabA");
  prefabA.GetComponent<Image>().color = new Color(1, 0, 0);
  

  Instead, you should always instantiate first before making changes:

  // ✅ Correct: Only modifies the runtime instance
  var prefabA = Resources.Load<GameObject>("PrefabA");
  var instance = Instantiate(prefabA);
  instance.GetComponent<Image>().color = new Color(1, 0, 0);
  

  Double-check your Project window: Select Prefab A and look at its Image component color in the Inspector. If it's not your default value, reset it and adjust your code to target only instances.

• Hidden scripts overwriting the color post-instantiation
  Even if your color-setting code runs without errors, another script (maybe added dynamically when loading other Prefabs, or on a parent/child object) might be overwriting the color after your code executes. Add debug logs to track this:

  // Right after setting the color
  Debug.Log($"Initial Image color set to: {GetComponent<Image>().color}");
  
  // In an Update method to monitor changes
  void Update()
  {
      Debug.Log($"Current Image color: {GetComponent<Image>().color}");
  }
  

  This will tell you if the color is being changed unexpectedly after your initial setup.

• Unity 2018 Beta Prefab System Bug
  2018 was a major overhaul for Unity's Prefab system (introducing nested Prefabs), and beta versions often have edge-case bugs. Loading/destroying other Prefabs might be corrupting the instance cache, leading to stale property values. Try these fixes:

  1. Clear your project cache: Go to Edit > Clear All Player Prefs and Edit > Project Settings > Editor > Clear Cache.
  2. Reimport Prefab A: Right-click the Prefab in the Project window and select Reimport.
  3. Test in a clean scene: Create a new scene, load only Prefab A, modify its color, then load/destroy a simple test Prefab, and reload Prefab A. If the issue doesn't occur here, it's tied to other elements in your original scene.

• Shared Material Conflicts
  If your Image uses a shared material (instead of a unique instance), modifying the color might affect all objects using that material, and subsequent loads could pick up a stale state. Force a unique material instance for your Image:

  var image = instance.GetComponent<Image>();
  image.material = new Material(image.material); // Create a unique instance
  image.color = new Color(1, 0, 0);
  

  This ensures your color changes only apply to that specific Image instance.

• Timing Issues from Activation/Deactivation
  If you're activating/deactivating Prefab A or its parent objects between loads, your color-setting code might run before the Image component is fully initialized. Try delaying the color set until the next frame:

  IEnumerator SetColorAfterFrame()
  {
      yield return null; // Wait one frame for initialization
      GetComponent<Image>().color = new Color(1, 0, 0);
  }
  
  // Call this coroutine instead of setting color directly
  StartCoroutine(SetColorAfterFrame());
  

内容的提问来源于stack exchange，提问作者user2088807