Right you can see what it should look like, left you see my current result.
Maybe anyone has a tip for me?

code:

---

    <Window Id="wndSomeWindow" Version="1">
        <Position Width="213" Height="145"/>
        <TitleBar>
            <AllowMinimize>false</AllowMinimize>
            <AllowClose>false</AllowClose>
        </TitleBar>
        <WindowTmpl>
            <Borders Type="None"/>
            <BackgroundColor>
                <Red>255</Red>
                <Green>0</Green>
                <Blue>255</Blue>
                <Alpha>255</Alpha>
            </BackgroundColor>
        </WindowTmpl>
    </Window>

---

I've tried to do things like that but it doesn't seem possible as child wnds inherit transparancy from the parent and can't obviously appear less transparent than that. Only option I think would be to change the rect to a custom one and apply it somehow

Well basically I just wanted to illustrate that I'd simply and only like to create a Plus window with totally transparent background - not more, not less. The question is therefore: is it possible to get a transparent-backgrounded plus window?