LaTeX listings package setup for export of code blocks

[Naresh Gurbuxani]

For documentclasses article and beamer, I would like to use two
different font sizes. I want to keep other settings in my init.el
file.  This is my set up in init.el:

(require 'ox-latex)
(setq org-latex-src-block-backend 'listings)
(add-to-list 'org-latex-packages-alist '("" "listings"))
(add-to-list 'org-latex-packages-alist '("" "color"))
(setq org-latex-listings-options
      '(("basicstyle" "\\fontfamily{lmtt}\\selectfont\\footnotesize")
        ("keywordstyle" "\\color{blue}")
        ("commentstyle" "\\color{olive}")
        ("stringstyle" "\\color{purple}")
        ("showspaces" "false")
        ("showstringspaces" "false"))
      )

For beamer, my org document has this setup:
#+LATEX_HEADER: \lstset{basicstyle=\fontfamily{lmtt}\setfont\tiny}

This does not seem to have an effect.  Is it possible to use
#+LATEX_HEADER: to override some of the settings in init.el?

Thanks,
Naresh