auto myLambda = [](auto&& x){ std::cout << x << '\n'; };

Google’s Material Design dark theme recommends using dark gray (#121212) as a dark theme surface color “to express elevation and space in an environment with a wider range of depth.” In addition, many designers recommend adding a subtle dark blue tint to dark grays when defining the color scheme. It tends to create a better dark tone for digital screens and a more pleasing dark UI color palette.