Summary bar in same color as grouping band

Hi!

I have to color the grouping summaries (WBS) the same as the corresponding grouping bands. Of course I tried this but it seems impossible.
First of all it seems impossible to filter for Summaries - there is a default Summary filter which cannot be found as bar filter. So I built a custom one filtering out all Activity Types...
Then I have to filter all (four) different WBS levels for defining each grouping summary color, but I cannot find a way to do this.

Any suggestion? Thanks in advance!

Regards, Luc