diff --git a/lv_core/lv_group.c b/lv_core/lv_group.c
index cfa40c2c7..13595ae86 100644
--- a/lv_core/lv_group.c
+++ b/lv_core/lv_group.c
@@ -297,6 +297,7 @@ lv_group_focus_cb_t lv_group_get_focus_cb(lv_group_t * group)
  */
 static void style_mod_def(lv_style_t * style)
 {
+#if LV_COLOR_DEPTH != 1
     /*Make the style to be a little bit orange*/
     style->body.border.opa = LV_OPA_COVER;
     style->body.border.color = LV_COLOR_ORANGE;
@@ -309,6 +310,13 @@ static void style_mod_def(lv_style_t * style)
     style->body.shadow.color = lv_color_mix(style->body.shadow.color, LV_COLOR_ORANGE, LV_OPA_60);
 
     style->text.color = lv_color_mix(style->text.color, LV_COLOR_ORANGE, LV_OPA_70);
+#else
+    style->body.border.opa = LV_OPA_COVER;
+    style->body.border.color = LV_COLOR_BLACK;
+    style->body.border.width = 3;
+
+#endif
+
 }
 
 #endif /*USE_LV_GROUP != 0*/
diff --git a/lv_misc/lv_color.h b/lv_misc/lv_color.h
index 886c0c34b..d0e0027b5 100644
--- a/lv_misc/lv_color.h
+++ b/lv_misc/lv_color.h
@@ -245,11 +245,15 @@ static inline uint32_t lv_color_to24(lv_color_t color)
 static inline lv_color_t lv_color_mix(lv_color_t c1, lv_color_t c2, uint8_t mix)
 {
     lv_color_t ret;
+#if LV_COLOR_DEPTH != 1
     ret.red =   (uint16_t)((uint16_t) c1.red * mix + (c2.red * (255 - mix))) >> 8;
     ret.green = (uint16_t)((uint16_t) c1.green * mix + (c2.green * (255 - mix))) >> 8;
     ret.blue =  (uint16_t)((uint16_t) c1.blue * mix + (c2.blue * (255 - mix))) >> 8;
-#if LV_COLOR_DEPTH == 24
+# if LV_COLOR_DEPTH == 24
     ret.alpha = 0xFF;
+# endif
+#else
+    ret.full = mix > LV_OPA_50 ? c1.full : c2.full;
 #endif
 
     return ret;