Created attachment 133824 [details]
Transparent context menu and pixel

SUMMARY
There is something curious about the context menu borders in desktop and qt5 applications (Okular, e.g.). On a light background, the edges look transparent, on a dark background they look gray. Also, on light backgrounds a pixel is drawn on each category divider line.

STEPS TO REPRODUCE
1. Click to display context menu
2. The context menu appears

OBSERVED RESULT
On a light background context menu border seems transparent and a pixel is drawn in separating lines

EXPECTED RESULT
When a context menu is displayed, regardless of whether the background is light or dark, the border must be consistent

SOFTWARE/OS VERSIONS
Operating System: KDE neon 5.20
KDE Plasma Version: 5.20.4
KDE Frameworks Version: 5.76.0
Qt Version: 5.15.1
Kernel Version: 5.4.0-56-generic
OS Type: 64-bit
Processors: 8 × AMD Ryzen 5 3500U with Radeon Vega Mobile Gfx
Memory: 9.7 GiB of RAM
Graphics Processor: AMD RAVEN

ADDITIONAL INFORMATION