diff --git a/README.md b/README.md
index a992987..4f1d0b1 100644
--- a/README.md
+++ b/README.md
@@ -120,10 +120,13 @@ from the same directory as this README resides in, or
 
 ### Extras
 
-The `extra` directory in the same directory as this README resides in contains a Chrome/Chromium and a Plank theme.
+#### Arc Firefox theme
+A theme for Firefox is available at https://github.com/horst3180/arc-firefox-theme
 
+#### Chrome/Chromium theme
 To install the Chrome/Chromium theme go to the `extra/Chrome` folder and drag and drop the arc-theme.crx or arc-dark-theme.crx file into the Chrome/Chromium window. The source of the Chrome themes is located in the source "Chrome/arc-theme" folder.
 
+#### Plank theme
 To install the Plank theme, copy the `extra/Arc-Plank` folder to `~/.local/share/plank/themes` or to `/usr/share/plank/themes` for system-wide use.
 Now open the Plank preferences window by executing `plank --preferences` from a terminal and select `Arc-Plank` as the theme.
 
diff --git a/extra/Chrome/arc-dark-theme.crx b/extra/Chrome/arc-dark-theme.crx
deleted file mode 100644
index 853842a..0000000
Binary files a/extra/Chrome/arc-dark-theme.crx and /dev/null differ
diff --git a/extra/Chrome/arc-darker-theme.crx b/extra/Chrome/arc-darker-theme.crx
new file mode 100644
index 0000000..e528be3
Binary files /dev/null and b/extra/Chrome/arc-darker-theme.crx differ
diff --git a/extra/Chrome/arc-dark-theme/images/theme_frame.png b/extra/Chrome/arc-darker-theme/images/theme_frame.png
similarity index 100%
rename from extra/Chrome/arc-dark-theme/images/theme_frame.png
rename to extra/Chrome/arc-darker-theme/images/theme_frame.png
diff --git a/extra/Chrome/arc-dark-theme/images/theme_frame_inactive.png b/extra/Chrome/arc-darker-theme/images/theme_frame_inactive.png
similarity index 100%
rename from extra/Chrome/arc-dark-theme/images/theme_frame_inactive.png
rename to extra/Chrome/arc-darker-theme/images/theme_frame_inactive.png
diff --git a/extra/Chrome/arc-dark-theme/images/theme_toolbar.png b/extra/Chrome/arc-darker-theme/images/theme_toolbar.png
similarity index 100%
rename from extra/Chrome/arc-dark-theme/images/theme_toolbar.png
rename to extra/Chrome/arc-darker-theme/images/theme_toolbar.png
diff --git a/extra/Chrome/arc-dark-theme/manifest.json b/extra/Chrome/arc-darker-theme/manifest.json
similarity index 96%
rename from extra/Chrome/arc-dark-theme/manifest.json
rename to extra/Chrome/arc-darker-theme/manifest.json
index 2860580..42dcc6e 100644
--- a/extra/Chrome/arc-dark-theme/manifest.json
+++ b/extra/Chrome/arc-darker-theme/manifest.json
@@ -1,5 +1,5 @@
 {
-   "description": "Arc-Dark theme for Chrome/Chromium",
+   "description": "Arc-Darker theme for Chrome/Chromium",
    "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC6RY/VX2xN/FFEQQwi4sSHGaMxF6cARCTsKKxmPhbics9qDIkZxxBqeM4TUhHDhgsZrxZsXAplyKnIjTEIdw96XDK34uF5cqLOG5vzFRIOAdFfCyC9HNupQGg3Vd8PKSVmLZz/2Xsu5zmvx+zz3VIDtNK+HaVktMhJnO9utBougQIDAQAB",
    "manifest_version": 2,
    "name": "Arc Darker",