Use black for fill_color and make fill_color=true by default

labelme/config/default_config.yaml

@@ -22,7 +22,7 @@ label_colors: null
 shape:
   # drawing
   line_color: [0, 255, 0, 128]
-  fill_color: [0, 255, 0, 64]
+  fill_color: [0, 0, 0, 64]
   vertex_fill_color: [0, 255, 0, 255]
   # selecting / hovering
   select_line_color: [255, 255, 255, 255]
@@ -62,7 +62,7 @@ fit_to_content:
 # canvas
 epsilon: 10.0
 canvas:
-  fill_drawing: false
+  fill_drawing: true
   # None: do nothing
   # close: close polygon
   double_click: close