[plt-scheme] Highlighting Scheme Code

Hi all,

I would like to have a function that highlights scheme code. I know
about code from slideshow but that highlights the code and returns a
pict. I need, once the code is highlighted, the color of each
character.

I think it is possible to do this given that drscheme itself has
probably to do this somehow since it has to highlight the code and
display the character on screen with the appropriate color, but how
does it do?

Cheers,

-- 
Paulo Jorge Matos - pocmatos at gmail.com
Webpage: http://www.personal.soton.ac.uk/pocm