diff --git a/FlatCAMApp.py b/FlatCAMApp.py
index 2db5c306..aa01b823 100644
--- a/FlatCAMApp.py
+++ b/FlatCAMApp.py
@@ -5943,10 +5943,18 @@ class App(QtCore.QObject):
     def on_toggle_grid_lines(self):
         self.report_usage("on_toggle_grd_lines()")
 
+        settings = QtCore.QSettings("Open Source", "FlatCAM")
+        if settings.contains("theme"):
+            theme = settings.value('theme', type=str)
+        else:
+            theme = 'white'
+
         if self.toggle_grid_lines is False:
             if self.is_legacy is False:
-                self.plotcanvas.grid._grid_color_fn['color'] = Color('dimgray').rgba
-
+                if theme == 'white':
+                    self.plotcanvas.grid._grid_color_fn['color'] = Color('dimgray').rgba
+                else:
+                    self.plotcanvas.grid._grid_color_fn['color'] = Color('#FFFFFFFF').rgba
             else:
                 self.plotcanvas.axes.grid(True)
                 try:
@@ -5957,7 +5965,10 @@ class App(QtCore.QObject):
             self.toggle_grid_lines = True
         else:
             if self.is_legacy is False:
-                self.plotcanvas.grid._grid_color_fn['color'] = Color('#FFFFFFFF').rgba
+                if theme == 'white':
+                    self.plotcanvas.grid._grid_color_fn['color'] = Color('#dededeff').rgba
+                else:
+                    self.plotcanvas.grid._grid_color_fn['color'] = Color('#000000FF').rgba
             else:
                 self.plotcanvas.axes.grid(False)
                 try:
diff --git a/README.md b/README.md
index 546dfe94..7993629f 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,7 @@ CAD program, and create G-Code for Isolation routing.
 - fixed a bug in the Merge functions
 - fixed the Export PNG function when using the 2D legacy graphic engine
 - added a new capability to toggle the grid lines for both graphic engines: menu link in View and key shortcut combo ALT+G
+- changed the grid colors for 3D graphic engine when in Dark mode
 
 12.10.2019
 
diff --git a/flatcamGUI/VisPyCanvas.py b/flatcamGUI/VisPyCanvas.py
index d332b697..c476b6be 100644
--- a/flatcamGUI/VisPyCanvas.py
+++ b/flatcamGUI/VisPyCanvas.py
@@ -86,8 +86,18 @@ class VisPyCanvas(scene.SceneCanvas):
         # grid1 = scene.GridLines(parent=view.scene, color='dimgray')
         # grid1.set_gl_state(depth_test=False)
 
+        settings = QSettings("Open Source", "FlatCAM")
+        if settings.contains("theme"):
+            theme = settings.value('theme', type=str)
+        else:
+            theme = 'white'
+
         self.view = view
-        self.grid = scene.GridLines(parent=self.view.scene, color='dimgray')
+        if theme == 'white':
+            self.grid = scene.GridLines(parent=self.view.scene, color='dimgray')
+        else:
+            self.grid = scene.GridLines(parent=self.view.scene, color='#dededeff')
+
         self.grid.set_gl_state(depth_test=False)
 
         self.freeze()