Diff comment styling with alternate color schemes looks off
When using a dark theme for code blocks in GitLab, the borders and background of diff discussions clash a bit. ![Screen_Shot_2018-11-26_at_4.02.47_PM](/uploads/8749e49af3100dc08c948e5af3ce7731/Screen_Shot_2018-11-26_at_4.02.47_PM.png) /cc @annabeldunstone @fatihacet
issue