The testing of the new feature is happening among a small number of alpha testers, technology website DroidLife reported yesterday.

As of now, the standard white background UI with black text is the only option available to users.

"Not only is Twitter testing a 'Night Mode', but different button placements, too. Twitter is also experimenting with hamburger slide-out menus, overflow buttons, as well as floating action buttons (FAB) for the composing of new tweets," the rpeort added.

Once rolled out, the 'Night Mode' UI will automatically replace the white background with a dark blue user interface paired with white text to make it easy on the eyes during the night.