Created attachment 182311 [details]
Left: nvim, correct bg, incorrect border. Right: plain new konsole window, incorrect bg.

SUMMARY

Konsole alters the colors i set in the colorscheme, but respects the same color set by nvim

STEPS TO REPRODUCE
1.  Open the coloscheme editor, set the background color to #1f1f22 (31,31,34)
2.  Using some eyedropper (KColorChooser) sample the color shown in colorscheme editor grid. 
I get #1b1b1e (27,27,30).
3.  Open a new konsole window with the colorscheme. sample the background color. its #1b1b1e (27,27,30)
4. start nvim, which is configured with the same bg color. Sample it, and it is correct: #1f1f22 (31,31,34)
5. Go back to the colorscheme editor, and edit the bg color. choose pick screen color, and sample the current background color. See that it will now display even darker. do this in a loop to converge to black.

OBSERVED RESULT
konsole darkens the bg color i set.

EXPECTED RESULT
konsole uses the exact color i set.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1
Kernel Version: 6.15.2-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7800X3D 8-Core Processor
Memory: 30.5 GiB of RAM
Graphics Processor 1: NVIDIA GeForce RTX 4070/PCIe/SSE2
Graphics Processor 2: NVIDIA GeForce RTX 4070/PCIe/SSE2

Konsole version 25.04.2

ADDITIONAL INFORMATION