diff --git a/client/src/pdd_u2_purchase_adapter.py b/client/src/pdd_u2_purchase_adapter.py
index 296313f..4028d62 100644
--- a/client/src/pdd_u2_purchase_adapter.py
+++ b/client/src/pdd_u2_purchase_adapter.py
@@ -1303,6 +1303,11 @@ class U2PddPurchaseAdapter(PddPurchaseAdapter):
                     "observed_page_kind": current_page_kind,
                 },
             )
+        # 完整遍历第二规格后，面板可能停在尺码列表末端，颜色节点已经
+        # 滑出当前控件树。必须先回到颜色区域，再用最新控件树确认原颜色；
+        # 否则“当前看不见”会被误报成“颜色发生变化”。
+        current_xml = self._restore_purchase_panel_color_region(current_xml)
+        root = _parse_xml(current_xml)
         if not _selected(root, expected_snapshot.selected_color):
             raise PddPurchaseError(
                 "PURCHASE_SPEC_CONTEXT_CHANGED",
@@ -1311,7 +1316,6 @@ class U2PddPurchaseAdapter(PddPurchaseAdapter):
                 diagnostics={"context_check": "selected_color"},
             )
 
-        current_xml = self._restore_purchase_panel_color_region(current_xml)
         try:
             dimension = self._size_candidate_collector(self._require_device())
         except PddCollectError as exc:
diff --git a/client/test/test_pdd_u2_purchase_adapter.py b/client/test/test_pdd_u2_purchase_adapter.py
index c6531fe..33dc4fb 100644
--- a/client/test/test_pdd_u2_purchase_adapter.py
+++ b/client/test/test_pdd_u2_purchase_adapter.py
@@ -260,10 +260,18 @@ class SoldOutRefreshPurchaseDevice(FakeDevice):
 class VerticallyScrolledColorPanelDevice(FakeDevice):
     """模拟 PDD 记住规格面板纵向位置。"""
 
-    def __init__(self, *, starts_at_top: bool, restores_on_swipe: bool = True):
+    def __init__(
+        self,
+        *,
+        starts_at_top: bool,
+        restores_on_swipe: bool = True,
+        selected_color: str = "",
+    ):
         super().__init__()
         self.at_color_top = starts_at_top
         self.restores_on_swipe = restores_on_swipe
+        self.selected_color = selected_color
+        self.selected_size = ""
         self.swipes = []
 
     def dump_hierarchy(self):
@@ -272,9 +280,20 @@ class VerticallyScrolledColorPanelDevice(FakeDevice):
         if self.mode == "home":
             return home_xml()
         if self.mode == "panel":
-            return vertically_scrolled_purchase_panel_xml(
+            xml_data = vertically_scrolled_purchase_panel_xml(
                 at_color_top=self.at_color_top
             )
+            if self.at_color_top and self.selected_color == "黑色":
+                xml_data = xml_data.replace(
+                    '<node text="黑色" clickable="true"',
+                    '<node text="黑色" selected="true" clickable="true"',
+                )
+            if self.at_color_top and self.selected_size == "均码":
+                xml_data = xml_data.replace(
+                    '<node text="均码" clickable="true"',
+                    '<node text="均码" selected="true" clickable="true"',
+                )
+            return xml_data
         return super().dump_hierarchy()
 
     def swipe(self, x1, y1, x2, y2, duration=0.0):
@@ -1098,6 +1117,87 @@ class U2PddPurchaseAdapterTest(unittest.TestCase):
         )
         adapter.close()
 
+    def test_apply_resolved_size_restores_hidden_selected_color_before_recheck(self):
+        clock = FakeClock()
+        device = VerticallyScrolledColorPanelDevice(
+            starts_at_top=False,
+            selected_color="黑色",
+        )
+        selected_sizes = []
+        snapshot = PurchaseSpecCandidateSnapshot.build(
+            goods_id="753136429979",
+            selected_color="黑色",
+            target_size="50公斤",
+            dimension_name="尺码",
+            observations=(PurchaseSizeObservation("均码", True),),
+            observed_at="2026-08-18T04:00:00Z",
+        )
+
+        def select_size(_device, _xml, target, **_kwargs):
+            selected_sizes.append(target)
+            device.selected_size = target
+            return True
+
+        adapter = U2PddPurchaseAdapter(
+            "USB-001",
+            device_service=PddDeviceService(connector=lambda _serial: device),
+            sleeper=clock.sleep,
+            monotonic=clock.monotonic,
+            select_size_fn=select_size,
+            size_candidate_collector=lambda _device: SpecDimension(
+                "size", "尺码", (DimensionValue("均码", True),)
+            ),
+        )
+        adapter.open_goods(GOODS_URL)
+        device.mode = "panel"
+
+        adapter.apply_resolved_size(snapshot, snapshot.candidates[0])
+
+        self.assertEqual(len(device.swipes), 1)
+        self.assertLess(device.swipes[0][1], device.swipes[0][3])
+        self.assertEqual(selected_sizes, ["均码"])
+        adapter.close()
+
+    def test_apply_resolved_size_stops_when_hidden_color_cannot_be_restored(self):
+        clock = FakeClock()
+        device = VerticallyScrolledColorPanelDevice(
+            starts_at_top=False,
+            restores_on_swipe=False,
+            selected_color="黑色",
+        )
+        selected_sizes = []
+        candidate_scans = []
+        snapshot = PurchaseSpecCandidateSnapshot.build(
+            goods_id="753136429979",
+            selected_color="黑色",
+            target_size="50公斤",
+            dimension_name="尺码",
+            observations=(PurchaseSizeObservation("均码", True),),
+            observed_at="2026-08-18T04:00:00Z",
+        )
+        adapter = U2PddPurchaseAdapter(
+            "USB-001",
+            device_service=PddDeviceService(connector=lambda _serial: device),
+            sleeper=clock.sleep,
+            monotonic=clock.monotonic,
+            select_size_fn=lambda *_args, **_kwargs: selected_sizes.append(True),
+            size_candidate_collector=lambda _device: candidate_scans.append(True),
+        )
+        adapter.open_goods(GOODS_URL)
+        device.mode = "panel"
+
+        with self.assertRaises(PddPurchaseError) as raised:
+            adapter.apply_resolved_size(snapshot, snapshot.candidates[0])
+
+        self.assertEqual(
+            raised.exception.code,
+            "PURCHASE_PANEL_COLOR_REGION_NOT_FOUND",
+        )
+        self.assertEqual(len(device.swipes), 2)
+        self.assertEqual(candidate_scans, [])
+        self.assertEqual(selected_sizes, [])
+        adapter.close()
+
     def test_apply_resolved_size_distinguishes_page_and_color_context_changes(self):
         resolved_size = "均码【80-120斤】"
         snapshot = PurchaseSpecCandidateSnapshot.build(
diff --git a/docs/client/06-quality-security.md b/docs/client/06-quality-security.md
index 7c1fe1e..2293140 100644
--- a/docs/client/06-quality-security.md
+++ b/docs/client/06-quality-security.md
@@ -123,6 +123,9 @@ Client 不保存或读取 `purchase.live_*` 手工授权设置。`purchase_mode`
   不轮询 Admin。只有 `matched` 响应的哈希、候选编号、原文和 options 都是本次候选的
   逐字副本时才继续。响应返回后重新完整遍历真机候选并复算哈希，页面、颜色或候选
   有任何变化都在可逆阶段停止。
+- 完整遍历第二规格可能把已选颜色滑出当前控件树。Admin 返回解析结果后，Client
+  必须先有界恢复到颜色区域，再读取最新控件树确认原颜色仍明确选中；无法恢复与
+  明确换色分别安全停止，不能把暂时不可见当作颜色已经变化，也不能跳过颜色复核。
 - 解析记录不能覆盖任务原始规格。成功结果同时保留原始规格、实际采用规格和
   `resolution_id`；解析失败不自动重新采购，已有不可逆标记时永远不调用规格解析。
 - 设置采购数量时先读取当前值；数量相同不聚焦输入框，小差值优先使用加减按钮。