[BUG] Background of icon in statuscolumn does does not match the statuscolumn background

[primeapple]

NeoVim Version

NVIM v0.8.3
Build type: Release
LuaJIT 2.1.0-beta3
Übersetzt von builduser

Features: +acl +iconv +tui

Describe the bug
On some colorschemes the statuscolumn is colored differently than the Background of the buffer.
Neotest seems to set the background of the icons, that appear in the statuscolumn when running a test, to the buffer background.

To Reproduce
Install and use https://github.com/rebelot/kanagawa.nvim as a colorscheme.
Use Neotest to run a test, see the icons with wrong background.

If really needed I can provide a custom init.lua, but this should be straightforward.

Additional context

I'm not 100% sure how to fix this. The easiest would be to get the background color of the statuscolumn and set the icon background accordingly. If this is not possible, you could give the user the option to set the background of the icons on their own.

[antoineco]

For reference, lewis6991/gitsigns.nvim solves this issue by defining two variations of sign highlights (normal + numhl/signcolumn):

https://github.com/lewis6991/gitsigns.nvim/blob/v0.8.1/doc/gitsigns.txt#L552-L556