Two nice tools for setting terminal colors:
- theme.sh, really cool, set terminal color from the command line; Terminal agnostic, works on any terminal with OSC 4/11 support (e.g st, kitty, iterm). It can be used in scripts.
- Gogh, Color Schemes For Ubuntu, Linux Mint, Elementary OS and all distributions that use Gnome Terminal, Pantheon Terminal, Tilix, or XFCE4 Terminal; initially inspired by Elementary OS Luna. Also works on iTerm for macOS.