Transparent PNGs in FvwmButtons

I have created a transparent png with gimo which I want to use as a background in FvwmButtons
Currently I load it using a ColorsetColorset 7 fg #000000, bg #ffffff, Pixmap $[fvwm_verz]/vorlagen/leiste2-transparent.png
it looks like this

When I try to add RootTransparent to the colorset I don’t get any satisfactory results.

as you can see, the whole background image is gone now.

Here you can see a shot of how it should look (created with gimp)

Can anyone help me to create a config that can do this?

Try adding a tint and shape option to the colorset.
Have you seen this example?

Ok, now I got the correct shape, but the outlines of the bar are still missingColorset 7 Transparent, fg #000000, bg #e5e5e5, Pixmap $[fvwm_verz]/vorlagen/leiste2-transparent.png, RootTransparent buffer, ALpha 73, Shape $[fvwm_verz]/vorlagen/leiste2-shape.png, Tint #e5e5e5 73
How can I get them back?

Well it seems that I can either have transparency or the dark border.
When I use the Colorset without RootTransparent The Pixmap is displayed flawlessly in the desired shape, but without transparency.
When I add RootTransparency the Pixmap isn’t displayed at all… just the shape with the tinting option, but it is transparent.