Adding night mode option to Firefox

Components

Firefox is an open source browser developed by Mozilla Foundation and it's subsidiary. It is a very beautiful application for browsing, downloading and surfing the internet.

Proposal

I would like the night mode option to be added to Firefox browser.

Mockups / Examples

I would like to use the browser on my phone for illustration

When you click on the menu option as shown by the arrow above, a box should appear in this form below

Select the night option to toggle between day and night as shown above. The night mode should appear like this

Benefits

This will help users to change the interface of their browser especially in the night to help conserve their battery life and in case of screen light the mode is more convenient to use in the night than day time