There’s theme.sh which makes it easy to change terminal themes on the fly. Works on any terminal with OSC 4/11 support which is almost every terminal. I use it with xfce4-terminal which is xterm based.
If you want a different theme per system with theme.sh the simple way would be to just add a one-liner to the .bashrc of each system, Ex:
echo "theme.sh tempus-autumn" >> ~/.bashrc
If you wanted to have it be directory specific or something else, you could do a bit of shell scripting in the .bashrc to make that happen (let me know if you need help).