diff --git a/src/app/modules/gfx.cpp b/src/app/modules/gfx.cpp
index f079a5139..b56308505 100644
--- a/src/app/modules/gfx.cpp
+++ b/src/app/modules/gfx.cpp
@@ -40,6 +40,22 @@ using namespace gfx;
 
 namespace {
 
+gfx::Color gridColor1()
+{
+  if (ui::is_ui_thread() && current_editor)
+    return color_utils::color_for_ui(current_editor->docPref().bg.color1());
+  else
+    return gfx::rgba(128, 128, 128);
+}
+
+gfx::Color gridColor2()
+{
+  if (ui::is_ui_thread() && current_editor)
+    return color_utils::color_for_ui(current_editor->docPref().bg.color2());
+  else
+    return gfx::rgba(192, 192, 192);
+}
+
 void draw_checked_grid(ui::Graphics* g,
                        const gfx::Rect& rc,
                        const gfx::Size& tile,
@@ -78,9 +94,7 @@ void draw_checked_grid(ui::Graphics* g,
                        const gfx::Rect& rc,
                        const gfx::Size& tile)
 {
-  draw_checked_grid(g, rc, tile,
-                    color_utils::color_for_ui(current_editor->docPref().bg.color1()),
-                    color_utils::color_for_ui(current_editor->docPref().bg.color2()));
+  draw_checked_grid(g, rc, tile, gridColor1(), gridColor2());
 }
 
 void draw_checked_grid(ui::Graphics* g,
@@ -88,9 +102,7 @@ void draw_checked_grid(ui::Graphics* g,
                        const gfx::Size& tile,
                        DocumentPreferences& docPref)
 {
-  draw_checked_grid(g, rc, tile,
-                    color_utils::color_for_ui(docPref.bg.color1()),
-                    color_utils::color_for_ui(docPref.bg.color2()));
+  draw_checked_grid(g, rc, tile, gridColor1(), gridColor2());
 }
 
 void draw_color(ui::Graphics* g,
@@ -192,8 +204,8 @@ void draw_alpha_slider(ui::Graphics* g,
 
   for (int x=0; x<rc.w; ++x) {
     const int a = (255 * x / xmax);
-    const doc::color_t c1 = doc::rgba_blender_normal(color_utils::color_for_ui(current_editor->docPref().bg.color1()), c, a);
-    const doc::color_t c2 = doc::rgba_blender_normal(color_utils::color_for_ui(current_editor->docPref().bg.color2()), c, a);
+    const doc::color_t c1 = doc::rgba_blender_normal(gridColor1(), c, a);
+    const doc::color_t c2 = doc::rgba_blender_normal(gridColor2(), c, a);
     const int mid = rc.h/2;
     const int odd = (x / rc.h) & 1;
     g->drawVLine(
@@ -220,8 +232,8 @@ void draw_alpha_slider(os::Surface* s,
   os::Paint paint;
   for (int x=0; x<rc.w; ++x) {
     const int a = (255 * x / xmax);
-    const doc::color_t c1 = doc::rgba_blender_normal(color_utils::color_for_ui(current_editor->docPref().bg.color1()), c, a);
-    const doc::color_t c2 = doc::rgba_blender_normal(color_utils::color_for_ui(current_editor->docPref().bg.color2()), c, a);
+    const doc::color_t c1 = doc::rgba_blender_normal(gridColor1(), c, a);
+    const doc::color_t c2 = doc::rgba_blender_normal(gridColor2(), c, a);
     const int mid = rc.h/2;
     const int odd = (x / rc.h) & 1;