diff --git a/tabulous/__init__.py b/tabulous/__init__.py
index 0df02a7..a4faa3b 100644
--- a/tabulous/__init__.py
+++ b/tabulous/__init__.py
@@ -1,4 +1,4 @@
-__version__ = "0.5.6.dev0"
+__version__ = "0.5.6"
 
 from tabulous.widgets import TableViewer, TableViewerWidget
 from tabulous.core import (
diff --git a/tabulous/_qt/_table/_base/_enhanced_table.py b/tabulous/_qt/_table/_base/_enhanced_table.py
index 1080364..2e5199c 100644
--- a/tabulous/_qt/_table/_base/_enhanced_table.py
+++ b/tabulous/_qt/_table/_base/_enhanced_table.py
@@ -584,6 +584,7 @@ def _get_highlight_color(self):
 
     def _set_highlight_color(self, value: QtGui.QColor):
         self._highlight_color = value
+        self._highlight_color.setAlpha(86)
         self.update()
 
     highlightColor = Property(QtGui.QColor, _get_highlight_color, _set_highlight_color)