-----
if [ -x /usr/share/source-highlight/src-hilite-lesspipe.sh ]; then
        export LESSOPEN="| /usr/share/source-highlight/src-hilite-lesspipe.sh %s"
        export LESS=' -R '
fi
-----

https://www.gnu.org/software/src-highlite/

https://packages.debian.org/jessie/source-highlight

http://packages.ubuntu.com/search?keywords=source-highlight