[O] [feature request] set text color and size

[zwz]

I made presentations with org-mode + beamer quite a lot.
Now and then I'd like to set a different color for some text 
to draw the students' attention. For example,
#+begin_src org
* test
  blah blah ...
  We should \textcolor{red}{NEVER} do it.
  ....
#+end_src 

As HTML5 slides are getting popular these days, I am trying org-mode +
HTML5. But I find I have to keep a separate edition of org file for
HTML5 slides from the beamer ones, since the color setting is quite
different.

Here comes my feature request: set text color in a consistent way.
We may introduce a new syntax and rewrite the test org-file above as follows:
#+begin_src org
* test
  blah blah ...
  We should [#ff0000 NEVER] do it.
  ....
#+end_src

In the brackets, the first item is the color to be set for the rest
text. And this item must start with #, followed by RGB hex numbers (css-like)
or a color name. If the format is not right, we can just treat it like
normal text. 

The syntax can be extended for setting text size as well. That is, #
followed by some numbers (ie. less than 6 numbers).