diff --git a/test/ascii-art.nas b/test/ascii-art.nas
index 05fb7b9..63417fb 100644
--- a/test/ascii-art.nas
+++ b/test/ascii-art.nas
@@ -139,6 +139,8 @@ var curve7=func(){
         p=p>=4?0:p;
     }
 }
+
+# enable unicode
 if(os.platform()=="windows")
     system("chcp 65001");
 trans_ttf("just for test");
diff --git a/test/bfs.nas b/test/bfs.nas
index 407b33b..f0dc14f 100644
--- a/test/bfs.nas
+++ b/test/bfs.nas
@@ -53,7 +53,8 @@ var bfs=func(begin,end){
     return;
 }
 
+# enable ANSI escape sequence
 if(os.platform()=="windows")
-    system("chcp 65001");
+    system("color");
 print("\ec");
 bfs([0,0],[9,19]);
\ No newline at end of file
diff --git a/test/filesystem.nas b/test/filesystem.nas
index a8ab44f..87b6347 100644
--- a/test/filesystem.nas
+++ b/test/filesystem.nas
@@ -30,6 +30,7 @@ var prt=func(s,path){
     }
 }
 
+# enable unicode
 if(os.platform()=="windows")
     system("chcp 65001");
 println("\e[33m[",unix.getcwd(),"]\e[36m>\e[0m");
diff --git a/test/life.nas b/test/life.nas
index 78ed0d4..cb2e1e9 100644
--- a/test/life.nas
+++ b/test/life.nas
@@ -29,8 +29,9 @@ var prt=func()
 }
 
 func(){
+    # enable ANSI escape sequence
     if(os.platform()=="windows")
-        system("chcp 65001");
+        system("color");
     print("\ec");
     rand(time(0));
     map=new_map();
diff --git a/test/qrcode.nas b/test/qrcode.nas
index 10530b9..6db4747 100644
--- a/test/qrcode.nas
+++ b/test/qrcode.nas
@@ -22,6 +22,7 @@ var code=[
     [1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
 ];
 
+# enable unicode
 if(os.platform()=="windows")
     system("chcp 65001");
 var texture=["  ","██"];
diff --git a/test/snake.nas b/test/snake.nas
index 00387fa..2311f7f 100644
--- a/test/snake.nas
+++ b/test/snake.nas
@@ -183,6 +183,7 @@ var co=coroutine.create(func(){
 });
 
 var main=func(){
+    # enable unicode
     if(os.platform()=="windows")
         system("chcp 65001");
     print("\ec");
diff --git a/test/wavecollapse.nas b/test/wavecollapse.nas
index 28fc14c..d667919 100644
--- a/test/wavecollapse.nas
+++ b/test/wavecollapse.nas
@@ -94,6 +94,7 @@ var map=func(){
     }
 }();
 
+# enable unicode
 if(os.platform()=="windows")
     system("chcp 65001");
 map.new(80);