diff --git a/src/render/interact/SliceTool.cpp b/src/render/interact/SliceTool.cpp
index 033fa9a..72d133d 100644
--- a/src/render/interact/SliceTool.cpp
+++ b/src/render/interact/SliceTool.cpp
@@ -152,10 +152,10 @@ void SliceTool::setSelected(bool sel) {
     // 切片边框 = widget 的 PlaneProperty：选中→亮黄粗线，未选中→暗灰细线。
     if (auto* prop = widget_->GetPlaneProperty()) {
         if (sel) {
-            prop->SetColor(1.0, 0.9, 0.1);
-            prop->SetLineWidth(3.0);
+            prop->SetColor(0.0, 0.95, 1.0);  // 亮青：与未选的暗灰强对比
+            prop->SetLineWidth(3.5);
         } else {
-            prop->SetColor(0.5, 0.5, 0.5);
+            prop->SetColor(0.35, 0.35, 0.4);  // 暗灰
             prop->SetLineWidth(1.0);
         }
     }