Vertical tabs have too little contrast with background

[TheRealGLH]

Which in turn means it's hard to see which tab is selected at a quick glance. If the sidebar is expanded, there's at least a button next to it but some more visual clarity would be ideal.

This is through the native, experimental implementation that can be enabled in about:config starting with Firefox 129:

Compared with regular horizontal tabs:

Version info:

[RaphGL]

I've assigned the issue to the creator of the userChrome theme, I'm only the maintainer of the browser theme extension.
But if you or others fix the issue and submit a PR, I'm willing to merge the request like I've done in the past.

[TheRealGLH]

I should have specified that this is about the browser theme extension version, not the userChrome theme.

[RaphGL]

Oh, so it's my version? I thought it was the userChrome one because you mentioned about:config lol, my bad.

I've went and enabled vertical bars and tried to spot where the issue is. I've managed to fix it. If you downloaded the theme from the Firefox Addons store then you should be getting the fix after firefox approves the changes