diff --git a/superset/assets/images/viz_thumbnails/country_map.png b/superset/assets/images/viz_thumbnails/country_map.png
index 3ac6c0985c..896fd6b09a 100644
Binary files a/superset/assets/images/viz_thumbnails/country_map.png and b/superset/assets/images/viz_thumbnails/country_map.png differ
diff --git a/superset/assets/images/viz_thumbnails/horizon.png b/superset/assets/images/viz_thumbnails/horizon.png
index 7ccd90f3ff..a5d4bf3ec4 100644
Binary files a/superset/assets/images/viz_thumbnails/horizon.png and b/superset/assets/images/viz_thumbnails/horizon.png differ