For reference, currently, theme options within the app only offer System Default, Light, and Dark. With the Google Play Beta Program's WhatsApp version 2.24.21.34, however, users on Android can expect to see up to 22 new chat themes with up to 20 different color options, as highlighted by WABetaInfo.

You get dozens of options for personalization. WhatsApp has been working on chat-specific theme support for a few months now, and the good news is that

Meta's WhatsApp is testing custom chat themes for enhanced personalisation, offering 22 themes and colour variations for select beta users. The app also expected to improve video calls with filters and backgrounds.

WhatsApp will soon allow users to customise their chats with a new chat theme feature. The feature is currently in beta testing. Once available, the feature will allow users to personalise individual chats with a variety of themes and colours.