Adjust color on homepage to match zen theme

[mr-cheffy]

What feature would you like to see?

The landing/homepage/newtab page has the custom zen logo, but the colorscheme isnt matched.
In firefox its matched to the rest of the UI, when using zed, its still firefox colors and not matched to the theme

What platform are you seeing the problem on?

Windows

Additional context

No response

~ Created automatically from issue: #480

[piscessafespace]

girls in stem would really appreciate you doing this <3 (im girls in stem)