diff --git a/color_test.go b/color_test.go
index b5fa65c..d790589 100644
--- a/color_test.go
+++ b/color_test.go
@@ -168,6 +168,8 @@ func TestRenderCode(t *testing.T) {
 	str = RenderString("36;1", "Text")
 	is.Equal("Text", str)
 	Enable = true
+
+	is.Empty(GetErrors())
 }
 
 func TestClearCode(t *testing.T) {
diff --git a/tag_test.go b/tag_test.go
index 5be19ae..19bf3c3 100644
--- a/tag_test.go
+++ b/tag_test.go
@@ -81,17 +81,21 @@ func TestParseCodeFromAttr(t *testing.T) {
 }
 
 func TestPrint(t *testing.T) {
+	is := assert.New(t)
+
+	s := Sprint()
+	is.Equal("", s)
+
 	// force open color render for testing
 	buf := forceOpenColorRender()
 	defer resetColorRender()
-	is := assert.New(t)
 
 	is.True(len(GetColorTags()) > 0)
 	is.True(IsDefinedTag("info"))
 	is.Equal("0;32", GetTagCode("info"))
 	is.Equal("", GetTagCode("not-exist"))
 
-	s := Sprint("<red>MSG</>")
+	s = Sprint("<red>MSG</>")
 	is.Equal("\x1b[0;31mMSG\x1b[0m", s)
 
 	s = Sprint("<red>H</><green>I</>")
diff --git a/utils_test.go b/utils_test.go
index 0fcc74d..ca322d4 100644
--- a/utils_test.go
+++ b/utils_test.go
@@ -28,9 +28,13 @@ func TestUtilFuncs(t *testing.T) {
 	is.NoError(os.Unsetenv("MSYSTEM"))
 	is.False(IsMSys())
 	_ = os.Setenv("MSYSTEM", oldVal)
+}
+
+func TestIsSupportColor(t *testing.T) {
+	is := assert.New(t)
 
 	// IsSupport256Color
-	oldVal = os.Getenv("TERM")
+	oldVal := os.Getenv("TERM")
 	_ = os.Unsetenv("TERM")
 	is.False(IsSupportColor())
 	is.False(IsSupport256Color())
@@ -59,6 +63,7 @@ func TestUtilFuncs(t *testing.T) {
 	// TERM
 	mockEnvValue("TERM", "tmux-256color", func(_ string) {
 		is.True(IsSupportColor())
+		is.Equal("TERM=tmux-256color", SupColorMark())
 	})
 
 	// TERM
@@ -66,6 +71,11 @@ func TestUtilFuncs(t *testing.T) {
 		is.True(IsSupportColor())
 	})
 
+	// TERM
+	mockEnvValue("TERM", "alacritty", func(_ string) {
+		is.True(IsSupportColor())
+	})
+
 	is.NoError(os.Setenv("TERM", "xterm-vt220"))
 	is.True(IsSupportColor())
 	// revert