Modify chapter.titlepage

Hi,

I want to customize my chapter titles beyond the posibilities of 
component.title.properties - I think.

All I want is a colored block before the text/title, but I don't get it 
work (in FO). If I try to do the task with borders (border-left), the 
border goes above my title. Doing the same thing with an image (gif), 
the image is outputed above my title.

Can you give me a hint?

regards
Marco