It seems that dark mode is one of the most requested features in today's app landscape. More and more apps are offering a dark interface alternative to their users which should help with battery life on devices with OLED displays. Google has already offered dark mode support for popular apps like YouTube and Maps and the latest addition is Google Photos. Version 4.17.0.249919200 of Google Photos will bring the new dark interface with muted accents colors. The folks over at XDA-Developers reported they've received the latest build with a working dark theme but for now it appears...
Source: https://www.gsmarena.com/google_photos_will_get_dark_mode_with_next_update-news-37404.php