I'm fairly new to emacs / the lisp language, and I've been struggling trying to customize this. By default, unused variables and things such as unused python imports show by default as a grey foreground with green wavy underline. I'd like to customize this, however customizing the face does not work. After looking into it, it seems to be set by lsp-mode's lsp-diagnostic-attributes list. However, I have not been able to find a solution that works for customizing it so I can remove the green wavy underline. Customizing lsp-lsp-flycheck-info-unnecessary-face had no effect, and the follow did not work which was the only solution I could find:
(add-to-list 'lsp-diagnostics-attributes '(unnecessary :background "dark gray"))
Has anyone had any success customizing this and would be able to point me towards a solution?