A dark mode for Whatsapp application is currently being developed as was reported by WABetaInfo.
As the creation of the app is completed the app the feature will be accessible through a new section under WhatsApp’s Settings menu titled Theme Settings.
The Theme Settings will present WhatsApp users with three options which you will have to choose between Light Theme, Dark Theme, and System Default.
The Light Theme is the standard WhatsApp colour scheme currently used in the application, while the Dark Theme adopts blue and black night colours instead.
When System Default is selected, WhatsApp will automatically detect which theme is used by your Android operating system and set the same theme within the application.
The Dark Theme option is still under development, and the new color scheme does not yet have a release date.