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+# contrast-ratio extension for gnome-shell
+
+Calculate contrast ratio for readability based on WCAG 2.0 recommendations. If
+you have `grabc` installed, you can also capture color from your screen by
+clicking on the color preview.
+
+This extension has been tested on gnome-shell 3.26 and 3.28. If you're using
+this extension in earlier versions of gnome-shell, please let me know so I can
+officially add it to supported versions.
+
+## Dependencies
+
+If you want to capture color from a pixel on your screen, install `grabc`
+
+    apt-get install grabc
+
+
+## Installation from git
+
+    git clone https://github.com/larissa/contrast-ratio.git ~/.local/share/gnome-shell/extensions/[email protected]
+
+Restart the shell and then enable the extension.
+
+
+## Known issues
+
+Picking a color from anywhere on screen is not supported on wayland for
+security reasons, so `grabc` (and any other color picking tool) won't work if
+you're using wayland.