Aside from its numerous features, the one handy feature that you can use is the Dark mode which turns the Signal app interface into dark colors. All you need is to follow these steps and you can enable dark mode in Signal app for mobile.
Step 1: Launch Signal app on your smartphone and tap on your profile icon at the top left corner, you will enter the Signal Settings.
Step 2: Tap on Appearance from the settings menu and on the next screen, tap on Theme and choose Dark from the popup.
If you choose System default, the Signal app will use the system’s default dark mode or light mode depending upon the mode you have chosen currently.
That was all about the dark mode on Signal app.