Thank you. But how?

I tried as mentioned above but to no avail-

einar wrote:You'll have to change SVG. Those are part of the graphic.

I fiddled around with a copy of /usr/share/kde4/apps/desktoptheme/default/widgets/panel-background.svgz, with little success

• I tried deleting every item with a squircle in Inkscape,.
• I gunzip'd panel-background.svgz and edited the XML file in an editor, manually deleting all the paths inside various id="south blahblah" groups ("south" since I place my panel at the bottom).
• I tried using the panel-background.svg from the Eleanora theme that someone recommended.

Setting the panel background in Desktop Theme Details to any of these gave me a hard-to-read transparent panel where the blue Kubuntu background shows through.

I guess what might work is to manually ungroup each item with the unwanted squircles, point to each graphic item in turn and delete as little as possible, then regroup the remaining items, somehow preserving the original group name. That's beyond my point and click abilities in Inkscape.

Is there a "hierarchy" mode in Inkscape where you can navigate the ID hierarchy, highlight items, then delete them?

Plasma has an awesome theming machine, but it makes simple changes almost impossible.