Getting rid of that black frame in Notification area.
Replace the borderthickness here
<scrollviewer layoutpos="client" id="atom(list)" xscrollable="false" xbarvisibility="never" yscrollable="true" ybarvisibility="always" borderthickness="rect(1rp,1rp,1rp,1rp)" sheet="common" accessible="true" accname="scrollviewer" accrole="list">
with
<scrollviewer layoutpos="client" id="atom(list)" xscrollable="false" xbarvisibility="never" yscrollable="true" ybarvisibility="always" borderthickness="rect(0rp,0rp,0rp,0rp)" sheet="common" accessible="true" accname="scrollviewer" accrole="list">
in taskbarcpl.dll to get this:
Or add a bordercolor after the borderthickness to change the color like here: