Solarized is apparently built-in to LXTerminal 0.3.0. One solution to your problem would be to upgrade to 0.3.0, which is available in the Stretch repository.
It doesn't look like LXTerminal is in Backports, so upgrading to Stretch would probably be necessary here.
Alternatively, if you don't want to upgrade your whole system just for that, you could try using solarized-termcolor-osc4 which is supposed to be a close approximation to Solarized.
If you download that .sh file and put it somewhere in your home directory, you'll just need to add a line in your ~/.bashrc to run the script every time your terminal starts. You'll probably need something like this on a new line in your ~/.bashrc:
~/solarized.sh
This assumes you save the file as solarized.sh in your home directory. Also, remember to set +x in your terminal (you only need to do this onceādon't put it in the .bashrc):
$ chmod +x ~/solarized.sh