Customize listings per language?

[Michael Gauland]

I often have several different babel languages in the same file. I'd
like to be able make them easily distinguished by language (such as
having a different background or shadow).

As far as I can tell, the listings package doesn't let me override
settings by language.

The best solution I've so far is to precede each block with a
directive, such as:

    #+ATTR_LATEX: :options rulesepcolor=\color{green}
    #+begin_src elisp

Any suggestions for a less error-prone solution?

Kind regards,
Mike