diff --git a/src/core/Data.lua b/src/core/Data.lua
index c5232296..a6ec72e8 100644
--- a/src/core/Data.lua
+++ b/src/core/Data.lua
@@ -209,18 +209,10 @@ local function loadModule(dir, name)
   -- cache explicitly when require cannot see the mounted tree.
   local CacheFs = require("src.import.CacheFs")
   local GameVersion = require("src.core.GameVersion")
-  local prefix = GameVersion.cachePrefix()
-  local path = prefix .. "data/generated/" .. name .. ".lua"
-  local saved = CacheFs.prefix
-  CacheFs.prefix = ""
-  local bytes = CacheFs.read(path)
-  CacheFs.prefix = saved
-  if type(bytes) ~= "string" then
-    -- Also try with CacheFs.prefix if the caller set it for this version.
-    bytes = CacheFs.read("data/generated/" .. name .. ".lua")
-  end
+  local path = "data/generated/" .. name .. ".lua"
+  local bytes = CacheFs.readActive(path)
   if type(bytes) == "string" then
-    local chunk, err = loadstring(bytes, "@" .. path)
+    local chunk, err = loadstring(bytes, "@" .. GameVersion.cachePrefix() .. path)
     if not chunk then return false, err or mod end
     return pcall(chunk)
   end
diff --git a/src/import/CacheFs.lua b/src/import/CacheFs.lua
index 5dc3ec58..1f19dc66 100644
--- a/src/import/CacheFs.lua
+++ b/src/import/CacheFs.lua
@@ -294,6 +294,24 @@ function CacheFs.read(rel)
   return love.filesystem.read(rel)
 end
 
+-- Read cache-relative `rel` for the active GameVersion when PhysFS may hide
+-- prefixed Blue/Yellow trees (fused NX mount hole). Same order Data:load
+-- already used: active version prefix with CacheFs.prefix cleared, then
+-- `rel` under the caller's CacheFs.prefix. Returns the bytes or nil.
+function CacheFs.readActive(rel)
+  local GameVersion = require("src.core.GameVersion")
+  local prefix = GameVersion.cachePrefix()
+  local saved = CacheFs.prefix
+  CacheFs.prefix = ""
+  local bytes = CacheFs.read(prefix .. rel)
+  CacheFs.prefix = saved
+  if type(bytes) ~= "string" then
+    bytes = CacheFs.read(rel)
+  end
+  if type(bytes) == "string" then return bytes end
+  return nil
+end
+
 -- does cache-relative `rel` exist as a file?
 function CacheFs.exists(rel)
   rel = withPrefix(rel)
diff --git a/src/render/Assets.lua b/src/render/Assets.lua
index 5f41af88..79ee9115 100644
--- a/src/render/Assets.lua
+++ b/src/render/Assets.lua
@@ -43,11 +43,28 @@ function Assets.resolve(path)
   return loader:derivedPath(rel) or path
 end
 
+-- When PhysFS hides Blue/Yellow prefixed trees (fused NX), load generated
+-- asset bytes the same way Data:load does via CacheFs.readActive.
+local function generatedFileData(resolved)
+  if type(resolved) ~= "string" or resolved:sub(1, #GENERATED) ~= GENERATED then
+    return nil
+  end
+  if exists(resolved) then return nil end
+  local bytes = require("src.import.CacheFs").readActive(resolved)
+  if type(bytes) ~= "string" then return nil end
+  return love.filesystem.newFileData(bytes, resolved)
+end
+
 function Assets.image(path)
   local resolved = Assets.resolve(path)
   local image = cache[resolved]
   if not image then
-    image = love.graphics.newImage(resolved)
+    local fileData = generatedFileData(resolved)
+    if fileData then
+      image = love.graphics.newImage(fileData)
+    else
+      image = love.graphics.newImage(resolved)
+    end
     cache[resolved] = image
   end
   return image
@@ -56,7 +73,12 @@ end
 -- pixel-level reads (tile-shift variants, the spinner strip blit) resolve
 -- the same way but stay uncached: the caller keeps the derived product
 function Assets.imageData(path)
-  return love.image.newImageData(Assets.resolve(path))
+  local resolved = Assets.resolve(path)
+  local fileData = generatedFileData(resolved)
+  if fileData then
+    return love.image.newImageData(fileData)
+  end
+  return love.image.newImageData(resolved)
 end
 
 function Assets.register(invalidate)
diff --git a/tests/engine/assets_version_fallback_test.lua b/tests/engine/assets_version_fallback_test.lua
new file mode 100644
index 00000000..b0be3f6d
--- /dev/null
+++ b/tests/engine/assets_version_fallback_test.lua
@@ -0,0 +1,90 @@
+-- Yellow/Blue-only NX: PhysFS may hide prefixed assets/generated trees.
+-- Assets must fall back through CacheFs.readActive like Data:load does.
+package.path = "./?.lua;./?/init.lua;" .. package.path
+if not _G.love then _G.love = require("tests.love_stub") end
+
+local T = require("tests.harness")
+local check = T.check
+local eq = T.eq
+
+local GameVersion = require("src.core.GameVersion")
+local CacheFs = require("src.import.CacheFs")
+local Assets = require("src.render.Assets")
+
+local PNG = "assets/generated/tilesets/reds_house.png"
+local savedPrefix = CacheFs.prefix
+local savedVersion = GameVersion.get()
+
+local function clearPath(path)
+  love.filesystem.remove(path)
+end
+
+-- --- readActive: Yellow-prefixed bytes without unprefixed PhysFS visibility
+GameVersion.set("yellow")
+CacheFs.prefix = ""
+love.filesystem.write("yellow/" .. PNG, "yellow-png-bytes")
+clearPath(PNG)
+eq(CacheFs.readActive(PNG), "yellow-png-bytes",
+  "readActive finds yellow/<rel> when unprefixed path is missing")
+
+-- --- Assets.image fallback (Yellow-only mount hole)
+Assets.flush()
+local img = Assets.image(PNG)
+check(img ~= nil, "Assets.image loads Yellow tileset via readActive fallback")
+eq(img.path, PNG, "fallback Image keeps the logical generated path name")
+
+-- --- Assets.imageData fallback
+local id = Assets.imageData(PNG)
+check(id ~= nil, "Assets.imageData loads Yellow tileset via readActive fallback")
+eq(id.path, PNG, "fallback ImageData keeps the logical generated path name")
+
+-- --- Blue prefix
+GameVersion.set("blue")
+Assets.flush()
+love.filesystem.write("blue/" .. PNG, "blue-png-bytes")
+clearPath(PNG)
+clearPath("yellow/" .. PNG)
+local blueImg = Assets.image(PNG)
+check(blueImg ~= nil, "Assets.image loads Blue tileset via readActive fallback")
+
+-- --- Red primary path (unprefixed file visible → no fallback needed)
+GameVersion.set("red")
+Assets.flush()
+love.filesystem.write(PNG, "red-png-bytes")
+clearPath("blue/" .. PNG)
+local redImg = Assets.image(PNG)
+check(redImg ~= nil, "Assets.image loads Red tileset from unprefixed path")
+eq(love.filesystem.read(PNG), "red-png-bytes",
+  "Red still stores generated assets at the save-dir root")
+
+-- --- Missing generated file: no invented bytes
+GameVersion.set("yellow")
+Assets.flush()
+clearPath(PNG)
+clearPath("yellow/" .. PNG)
+clearPath("blue/" .. PNG)
+eq(CacheFs.readActive(PNG), nil,
+  "readActive returns nil when the file is absent in every tree")
+
+-- --- Non-generated paths never hit the versioned asset tree
+love.filesystem.write("yellow/" .. PNG, "should-not-leak")
+eq(CacheFs.readActive("assets/launcher/missing_chip.png"), nil,
+  "readActive does not remap unrelated paths onto yellow generated assets")
+
+-- --- readActive with CacheFs.prefix set (Data:load second try)
+GameVersion.set("yellow")
+CacheFs.prefix = "yellow/"
+love.filesystem.write("yellow/data/generated/maps.lua", "return { ok = true }")
+local luaBytes = CacheFs.readActive("data/generated/maps.lua")
+check(type(luaBytes) == "string" and luaBytes:find("ok", 1, true),
+  "readActive still finds yellow/data/generated when CacheFs.prefix is set")
+
+CacheFs.prefix = savedPrefix
+GameVersion.set(savedVersion)
+Assets.flush()
+clearPath(PNG)
+clearPath("yellow/" .. PNG)
+clearPath("blue/" .. PNG)
+clearPath("yellow/data/generated/maps.lua")
+
+T.finish()
diff --git a/tests/love_stub.lua b/tests/love_stub.lua
index 61cfa6d7..7f79ba3a 100644
--- a/tests/love_stub.lua
+++ b/tests/love_stub.lua
@@ -40,8 +40,15 @@ local gstate = { shader = nil, canvas = nil, blend = "alpha",
 local gstack = {}
 
 stub.graphics = {
-  newImage = function(path)
-    local w, h = pngSize(path)
+  newImage = function(pathOrData)
+    local path = pathOrData
+    if type(pathOrData) == "table" and pathOrData._fileData then
+      path = pathOrData.name or "<filedata>"
+    elseif type(pathOrData) == "table" and pathOrData.path then
+      path = pathOrData.path
+    end
+    local w, h = 8, 8
+    if type(path) == "string" then w, h = pngSize(path) end
     return setmetatable({ w = w, h = h, path = path }, Image)
   end,
   newQuad = function(x, y, w, h) return { x = x, y = y, w = w, h = h } end,
@@ -120,12 +127,22 @@ stub.filesystem = {
   write = function(name, content) files[name] = content return true end,
   read = function(name) return files[name] end,
   remove = function(name) files[name] = nil return true end,
+  newFileData = function(contents, name)
+    return { _fileData = true, contents = contents, name = name or "" }
+  end,
+  createDirectory = function() return true end,
   -- directories are implied by key prefixes ("mods/x/manifest.json")
-  getInfo = function(name)
-    if files[name] then return { type = "file" } end
+  getInfo = function(name, filter)
+    if files[name] then
+      if filter and filter ~= "file" then return nil end
+      return { type = "file" }
+    end
     local prefix = name .. "/"
     for key in pairs(files) do
-      if key:sub(1, #prefix) == prefix then return { type = "directory" } end
+      if key:sub(1, #prefix) == prefix then
+        if filter and filter ~= "directory" then return nil end
+        return { type = "directory" }
+      end
     end
     return nil
   end,
@@ -215,6 +232,30 @@ stub.mouse = {
 
 stub.timer = { getTime = function() return 0 end }
 
+-- Minimal image module so Assets.imageData can decode FileData fallbacks
+-- headless (full pixel stubs live in tests/mod_graphics_tests.lua).
+local ImageData = {}
+ImageData.__index = ImageData
+function ImageData:getWidth() return self.w end
+function ImageData:getHeight() return self.h end
+function ImageData:getDimensions() return self.w, self.h end
+function ImageData:getPixel() return 0, 0, 0, 1 end
+function ImageData:setPixel() end
+function ImageData:mapPixel() end
+function ImageData:encode() return { getString = function() return "" end } end
+
+stub.image = {
+  newImageData = function(a, b)
+    if type(a) == "table" and a._fileData then
+      return setmetatable({ w = 8, h = 8, path = a.name, source = a }, ImageData)
+    end
+    if type(a) == "string" then
+      return setmetatable({ w = 8, h = 8, path = a }, ImageData)
+    end
+    return setmetatable({ w = a or 8, h = b or 8 }, ImageData)
+  end,
+}
+
 -- Desktop / headless: full-window safe area (matches LÖVE's fallback).
 stub.window = {
   getSafeArea = function()