[TYPO3] Select a color according to the active level 1 menu item

[Joerg Wagner - DigiLog multimedia]

Hi all!

I want to adjust colors of parts of the page according to the top menu item 
that is currently selected.
In other words:
The site has say 5 menu topics on level 1 and the content of all pages 
should be colored according to the level 1 menu topic that is currently 
selected (even if a subpage of it is selected). A kind of color scheme for 
basic website categories.

I am chewing on TSref for hours now, but haven't even got a clue, what the 
right approach for this problem is.
I would have to get an ordinal numbering of the top menu items and then 
determine which number the currently active top menu item has.
Then I could select a color (I have defined them in TS Constants) according 
to this number.

Any help is welcome - even if it is only hints which approach to take.
Many thanks!

--
Jörg Wagner
DigiLog multimedia