presentations

[Patrick Gundlach <gundlach@irb.cs.uni-dortmund.de>]

Hi,

i would like to make a presentation with the following feature:

item 1

item 2 

item 3

first, item 1 is displayed in black and the other two items in 
grey. Second the first and second items are displayed in black 
and number three in grey and at last, all three items are 
displayed in black.

And, as an additional problem:
is it possible to define two colors a and b and another color c
which is "in the middle" of a and b? Something like c=(a+b)/2? 
That is for the problem above where the shadowed items should 
not be displayed in grey but in the color that is closer to the 
current backgroundcolor.

As far as I have seen, the \presentationstep does not do this. (module
pre-general)
(And, additionally it seems to be broken if one goes to the 
beginning of the document and try to do the steps 
again.)

Viele Grüße,

  Patrick Gundlach

- I TeX, therefore I am -